3 letters:
eid, i'd, ide, ede

4 letters:
bide, died, dyed, eide, eyed, fide, heid, hide, hyde, lide, lied, lyde, pied, ride, seid, side, syed, tide, tied, vide, vied, wide, bead, bede, cede, dede, deed, eade, fede, feed, he'd, heed, lead, leed, mead, nead, need, nied, peed, read, reed, reid, ried, seed, teed, we'd, weed, wied

5 letters:
-cide, -eyed, -wide, abide, alide, aride, aside, azide, b.i.d, beide, betid, breid, bride, chide, clyde, cried, dried, eneid, eq-5d, exide, flied, fride, fried, geide, glide, glied, gnide, gride, gryde, guide, guyed, heide, imide, iride, iside, kleid, obeid, oxide, plied, pride, pried, pryde, q.i.d, rheid, seide, shide, shied, skyed, sleid, slide, snide, spied, stied, t.i.d, teide, tride, tried, why'd, woeid, wried, wyden, ylide, -pede, abcde, abeed, aidid, alkyd, amiid, areed, baiid, beede, bleed, brede, breed, caede, canid, cpuid, cread, crede, creed, deede, dev.d, diede, dovid, dreed, erede, fleed, frede, freed, freid, gaede, glead, glede, gleed, grede, greed, hadid, hafid, hamid, i.e.d, keyed, knead, kneed, leede, libid, m.b.d, madid, meade, o.e.d, omead, piede, plead, prede, preed, q.e.d, reede, rheed, riede, saeed, seeed, she'd, sheed, skeed, skied, smead, smeed, snead, sneed, spaed, spead, spede, speed, steed, swede, teiid, thede, theed, tiede, treed, tweed, vahid, veede, vrede, vreid, wahid, walid, weede, wrede

6 letters:
a-side, abside, affied, alcide, allied, apside, arride, aspide, b-side, belied, beside, betide, cofide, cyanid, dafydd, decide, defied, denied, deride, divide, excide, halide, incide, inside, insyde, iodide, kreide, lti dd, lucide, muride, nikeid, onside, oreide, oxhide, pyside, relied, reside, retied, scheid, scried, sighed, stride, tineid, undyed, unhide, untied, upside, ureide, accede, adrede, agreed, amriid, anteed, asread, atrede, axseed, breede, decede, delead, deseed, emceed, exceed, expede, expeed, fareed, fleadh, friede, gilead, hameed, impede, incede, indeed, infeed, jameed, jereed, lipide, naveed, pitied, rashid, recede, remede, reread, reseed, sayiid, schede, screed, secede, shahid, sinead, spreed, streed, tawhid, thiede, unfeed, uplead, waheed, waleed

7 letters:
airside, alibied, anilide, applied, araneid, arnside, astride, avalide, avicide, azanide, bastide, bayside, bedside, beileid, biocide, bogside, bromide, bugeyed, carbide, clupeid, collide, confide, cowhide, cyanide, cyclide, dayside, debride, decried, deeside, deicide, deified, depside, diamide, dioxide, discide, dyazide, ebbtide, ecocide, edified, emeside, endride, energid, epoxide, farside, garside, gibside, glucide, gluside, glycide, hayride, hydlide, hydride, implied, inlaied, isatide, ivoride, joyride, joyryde, lactide, liquide, lowside, mcbride, mcbryde, medlied, meineid, methide, mouride, nuclide, offside, opetide, outride, outside, overrid, ovicide, ox-eyed, oxamide, ozonide, peptide, perseid, popeyed, preside, protide, provide, rawhide, reified, replied, retried, riptide, scheide, schmied, schneid, seaside, subside, suicide, sulfide, tayside, tenside, thighed, topside, unified, unkeyed, untried, uranide, vistide, volfied, wayside, wilhide, zimride, zincide, agamede, al-adid, allseed, aniseed, anobiid, arctiid, ashmead, ashweed, ausrede, bebleed, benweed, brighid, burweed, compeed, concede, cowweed, cudweed, decreed, degreed, despeed, diomede, discede, dispeed, dyeweed, emplead, epicede, fanweed, fitweed, ganymed, glochid, goateed, gumweed, hagseed, hayseed, hogweed, imbreed, implead, inbreed, inkneed, jamshid, jerreed, jetbead, kinrede, kynrede, laclede, letheed, limeade, linseed, lygaeid, matweed, mayweed, misdeed, misfeed, mislead, misread, mistide, monacid, mugweed, nasheed, neuwied, nitweed, oarweed, oilseed, oreweed, outrede, outweed, pigweed, pinweed, precede, preceed, procede, proceed, ragweed, rasheed, redweed, regrede, ruaridh, rurikid, schmead, schwede, seaweed, shaheed, succeed, sybreed, taeniid, tarweed, tupaiid, untread, upbreed

8 letters:
accuride, actinide, aerified, aldehyde, alfenide, algicide, alkoxide, alscheid, aphicide, arachide, arsenide, astatide, autocide, azoimide, backside, backslid, bankside, basified, bescheid, bestride, big-eyed, binoxide, blastide, bonafide, brontide, bug-eyed, burnside, casefied, cat-eyed, ceramide, citified, cityside, citywide, cockeyed, codified, coincide, complied, cragside, culicide, cup-tied, cupolaed, curbside, cytocide, darkseid, democide, descried, desonide, diiodide, dinoxide, diopside, diureide, dockside, doe-eyed, downside, dry-eyed, eastside, ethoxide, eventide, fatimide, felicide, femicide, feticide, filicide, fireside, flipside, flipsyde, flouride, fluoride, foreside, freeride, fripside, gartside, gasified, genocide, genoside, genozide, getreide, gilbride, glenside, hawkeyed, highside, hillside, hocktide, hog-tied, homicide, humified, ignified, ironside, itopride, kerbside, kilbride, kingside, lakeside, landside, langside, lapicide, lawnside, lee side, lisuride, low tide, macbride, mafenide, malahide, malamide, medicide, megimide, minified, misguide, mitglied, miticide, modified, mucamide, murexide, nearside, nidified, noontide, notified, nucleide, occupied, off-side, oleamide, on-glide, one-eyed, openside, ossified, outcried, outslide, override, overside, owl-eyed, pacified, parkside, parleyed, peroxide, phialide, pie-eyed, pig-eyed, pimozide, pin-eyed, piramide, plasmide, plastide, polypide, poolside, pop-eyed, portside, pulicide, purified, quayside, ramified, rarified, raticide, ratified, red-eyed, redivide, regicide, riboside, ringside, roadside, rutoside, salified, sam hyde, schneide, selenide, senicide, setaside, sevareid, shipside, sicklied, silicide, skyguide, sodamide, speyside, storeyed, suboxide, supplied, surfside, suroxide, tameside, taxiride, teesside, tepefied, thiazide, top side, triamide, trioxide, tyneside, typified, tyrannid, uglified, umscheid, undecide, undenied, urbicide, vaticide, veilside, verified, viricide, virucide, vivified, walleyed, weakside, westside, wikified, woodside, xenocide, yuletide, agueweed, airspeed, almsdeed, alwaleed, anisakid, antecede, aristede, aristide, bindweed, birdfeed, blueweed, bullweed, bur-reed, bur reed, buzzfeed, capeweed, centiped, clotweed, cockweed, coleseed, copyread, daneweed, dasyatid, dilaudid, dillweed, downweed, duckweed, elfriede, enschede, filariid, fireweed, flambeed, flaxseed, flaxweed, flixweed, ganymede, gapeseed, goatweed, goutweed, gulfweed, hag-seed, handfeed, hawkweed, hurdleed, illbleed, imbureed, ironweed, itchweed, knapweed, knopweed, knotweed, lakeweed, lockheed, locoweed, markweed, mesaieed, milkweed, misplead, moonseed, mujtahid, neckweed, netspeed, newsfeed, nobody'd, oarsweed, octopede, one-seed, ophidiid, oribatid, outbreed, outspeed, overfeed, overlead, overread, pay heed, pineweed, pokeweed, pondweed, rapeseed, reduviid, refereed, richweed, rockweed, rosemead, s-cry-ed, silkweed, silpheed, snapweed, soapweed, stampede, strokeed, subbreed, suisuide, sylpheed, tatusiid, tee-heed, teelseed, tickseed, tickweed, tileseed, trusteed, unpitied, usamriid, vandread, wartweed, wee-weed, yaw-weed, zakspeed

9 letters:
acaracide, acaricide, acetamide, acetified, acetonide, acetylide, acidified, algaecide, alongside, aluminide, ambleside, amebicide, amicicide, amplified, androcide, anglified, apartheid, assegaied, backslide, barbicide, barmecide, beachside, beatified, bemegride, bensulide, benzamide, bicyanide, biguanide, biniodide, bird-eyed, bisulfide, blindside, bloodride, blowdried, blue-eyed, bona-fide, bona fide, boss-eyed, broadside, brookside, brutified, buck-eyed, bullycide, c-peptide, calcified, carbamide, carbimide, carbonide, carboxide, certified, cervicide, cetrimide, cheapside, clarified, clopamide, cock-eyed, cold-eyed, cornified, courtside, coverside, crucified, cyamelide, damnified, dandified, dark-eyed, deep-eyed, densified, deuteride, deutoxide, dewy-eyed, diazoxide, dibromide, dicyanide, dignified, dipeptide, disulfide, dove-eyed, downslide, dulcified, dull-eyed, earthwide, east side, elmaguide, encainide, ethnocide, etoposide, euphotide, europride, evil-eyed, exenatide, falsified, fire-eyed, floodtide, flutamide, foeticide, fongicide, formamide, formicide, fortified, four-eyed, frog-eyed, frontside, frusemide, fungicide, germicide, glatified, glipizide, globeride, globoside, glorified, glucoside, glyburide, glyceride, glycolide, glycoside, gratified, graveside, greenside, grey-eyed, gynaecide, hawk-eyed, heaviside, herbicide, herzeleid, high tide, horrified, horsehide, hydramide, hydrazide, ingleside, in stride, iopromide, isomeride, jellified, justified, keen-eyed, koodevide, lactamide, lactimide, landslide, larvacide, larvicide, lay aside, left-eyed, lignified, lipoamide, liquefied, liquified, lithified, low-keyed, lullabied, lynx-eyed, lysergide, macrolide, magneride, magnified, maleimide, matricide, mefruside, mellonide, methoxide, metiamide, metrified, microzide, misdivide, mogroside, mole-eyed, mollified, moon-eyed, mope-eyed, mortified, mosapride, mummified, muscicide, mystified, naphthide, naugahyde, nialamide, nightride, nightside, nitrified, northside, nullified, oceanside, off-glide, oftentide, opacified, open-eyed, otherside, outstride, overglide, overslide, oxanilide, panoplied, paraglide, parricide, patricide, pentoside, pentoxide, pergolide, periodide, pesticide, petrified, phenoxide, phthalide, pink-eyed, piscicide, planeside, polyamide, polyimide, pool-side, prolicide, protoxide, putrified, qualified, queenside, reapplied, rectified, remscheid, reunified, riskified, riverside, rockslide, satisfied, scabicide, scarified, scorified, set-aside, set aside, shadyside, shoreside, siblicide, signified, sissified, skew-eyed, slit-eyed, sloe-eyed, snapguide, snowslide, sore-eyed, sous-vide, southside, specified, sphragide, sporicide, stateside, statewide, storewide, suavified, subdivide, sulfamide, sulfatide, sulfoxide, sulpiride, sunnyside, tableside, tailslide, telluride, teniacide, teprotide, terrified, testified, tocainide, torpified, trackside, trailside, triiodide, unapplied, unascried, underside, undertide, unprovide, uxoricide, verbicide, verbified, vermicide, versified, vitrified, volkslied, vulpicide, wall-eyed, war bride, waterside, waveguide, weak-eyed, weedicide, westpride, west side, whernside, whiteside, wide-eyed, wild-eyed, winefride, wittified, worldwide, yuppified, zombicide, zombified, al-tawhid, appleseed, benniseed, bergfried, blackseed, bloodweed, brookweed, broomweed, bugleweed, candyweed, cane reed, capripede, catchweed, centipede, cerripede, chafeweed, chaffweed, cheerlead, chia seed, chickweed, cirrepede, cirripede, clearweed, colicweed, crazyweed, dill seed, dill weed, disagreed, ditchweed, dodecafid, driftweed, drip-feed, drop-seed, estrildid, fern seed, feverweed, filagreed, filigreed, flamsteed, footspeed, free-reed, frostweed, gelechiid, goodspeed, grapeseed, greenweed, growthead, gypsyweed, halfbreed, hand-feed, hatebreed, highspeed, horseweed, hydroseed, intercede, intermede, janjaweed, jewelweed, jointweed, krumwiede, line feed, matchweed, microbead, millepede, millipede, mini-feed, nosebleed, notchweed, off-speed, orangeade, overbreed, overspeed, pearlweed, pedigreed, pine-weed, poeciliid, poppyseed, proofread, purebreed, reparteed, retrocede, riverweed, rosinweed, runnemede, runnymede, sand reed, saturniid, selespeed, self-seed, siegfried, sightread, skunkweed, smartweed, snakeweed, soap-weed, spoonfeed, squawweed, stellerid, stickseed, stickweed, stinkweed, stoneweed, supercede, supersede, superweed, sweetweed, symphilid, take heed, ten-speed, tick-weed, two-speed, undecreed, underfeed, waterweed, whiteweed, windspeed, witchweed, wolfspeed, womanhede

10 letters:
aborticide, acecainide, adulticide, alkalamide, alkalified, almoravide, amcinonide, ammonified, anagrelide, anandamide, antimonide, argus-eyed, ascaricide, audioguide, beady-eyed, beautified, bifluoride, black-eyed, blear-eyed, blind-side, blink-eyed, broad-side, brokencyde, budesonide, bufanolide, bumetanide, burimamide, cantharide, canyonside, capacified, cast aside, ceforanide, classicide, classified, clear-eyed, countywide, cross-eyed, daintified, daminozide, debit side, denazified, detoxified, diselenide, disprovide, dollarhide, dominicide, doublewide, drip-dried, eagle-eyed, eastertide, eingeweide, elfen lied, emulsified, esterified, etherified, europewide, familicide, feel pride, filaricide, flecainide, flood tide, fluoboride, fratricide, fructified, fructoside, furosemide, gametocide, gendercide, genericide, gentrified, gliclazide, green-eyed, groundside, hair slide, hang-glide, hang glide, harborside, hearthside, high-keyed, honeyguide, humanicide, humberside, hydriodide, hyperglide, hyperoside, hyperoxide, identified, ifosfamide, indapamide, indogenide, inverclyde, iron-oxide, isocyanide, isosorbide, kais saied, lacosamide, lammastide, lanthanide, lapidified, laurentide, lententide, leuprolide, linguicide, loperamide, lumbricide, mariticide, marketwide, mercaptide, merseyside, misapplied, misty-eyed, multiplied, nationwide, nematicide, nematocide, night-eyed, nilutamide, nimesulide, nonivamide, north side, nucleoside, nucleotide, octreotide, ophicleide, overstride, oxyuricide, panzerlied, pearl-eyed, perbromide, percarbide, persulfide, phytoncide, planetside, politicide, polyiodide, polyketide, populicide, powerglide, preprovide, prettified, princified, proglumide, pseudocide, push aside, pyranoside, quantified, reoccupied, resupplied, revivified, rhamnoside, right-eyed, rigidified, round-eyed, saccharide, salicylide, sanctified, saponified, schoolwide, scrofulide, self-pride, semiramide, shanghaied, sharp-eyed, shrovetide, silicified, silverside, simplified, singlewide, slack tide, slant-eyed, solidified, sororicide, south side, spermicide, springtide, stalk-eyed, staurotide, stevioside, stillicide, stratified, streamside, stromateid, stultified, sulodexide, sulphamide, sulphinide, sulphoxide, summerside, summertide, superoxide, systemwide, taeniacide, take pride, tartramide, teary-eyed, teniposide, the upside, thrum-eyed, tolazamide, torasemide, tribromide, tripeptide, trisulfide, uncodified, undescried, unmodified, unoccupied, unossified, unpacified, unpurified, unratified, unsupplied, unverified, upper side, valeramide, vogelweide, waterslide, wave guide, well-tried, wintertide, withinside, with pride, world-wide, worldpride, xanthamide, young-eyed, ziconotide, zinc oxide, zonisamide, abdelhamid, beetleweed, beggarweed, bitterweed, black bead, bottlefeed, broom-weed, butterweed, buttonweed, cancerweed, cankerweed, carpetweed, clammyweed, colorbreed, cottonseed, cottonweed, crazy weed, creep feed, crossbreed, diphenamid, ditch reed, enterplead, euphausiid, float-feed, force-feed, force feed, friendfeed, frost-weed, garnisheed, ghost weed, giant reed, gigi hadid, gossiprede, gravelweed, guaranteed, guarantied, half-breed, heartbleed, hemerobiid, high-speed, hoverspeed, hyperspeed, interbreed, interplead, jimsonweed, libellulid, lightspeed, lymantriid, mazdaspeed, nightbreed, pearl-weed, poppy seed, quirk bead, rabbitweed, rattleweed, rebamipide, scarabaeid, silverweed, skunk-weed, sneezeweed, spoon-feed, stall-feed, stick-seed, superspeed, thamesmead, title deed, trust deed, tumbleweed, velocipede, velvetweed, wattleseed, weak-kneed, white bead, will smeed, winterfeed, winterweed, yellowweed, zaha hadid

11 letters:
acetanilide, acraldehyde, aldactazide, almond-eyed, amisulpride, apalutamide, arabinoside, aurocyanide, bactericide, benserazide, bentiromide, benzanilide, bleary-eyed, boost-glide, borohydride, bright-eyed, bright side, brush aside, butterflied, carboxamide, carbutamide, cardenolide, cerebroside, chondrified, civic pride, client-side, color-keyed, commodified, companywide, countrified, countrycide, countryside, countrywide, credit side, cross-slide, cyanuramide, decalcified, decapeptide, decertified, demand-side, demystified, denitrified, deslanoside, devitrified, diglyceride, direct tide, disaccharid, diversified, double-eyed, double-wide, dulaglutide, dutasteride, electrified, empanoplied, enfuvirtide, exemplified, fenretinide, finasteride, foundryside, frenchified, furaldehyde, galactoside, ganglioside, giganticide, gimlet-eyed, ginsenoside, glassy-eyed, glimepiride, glucuronide, glycuronide, goggle-eyed, goldschmied, halcinonide, heptameride, hollow-eyed, honey guide, hydrogenide, incesticide, indemnified, infanticide, insecticide, intensified, ketcherside, leflunomide, liberticide, linaclotide, lipopeptide, liraglutide, mafosfamide, malignified, meglitinide, metaldehyde, microbicide, moclobemide, morningside, morningtide, nateglinide, neonaticide, niclosamide, nikethamide, nonapeptide, objectified, octapeptide, on the side, outjockeyed, oxaluramide, paraldehyde, parasuicide, parenticide, passiontide, personified, phenacemide, phosphatide, phthalimide, polybromide, polypeptide, polysulfide, potassamide, pramlintide, preachified, preoccupied, pretypified, purple-eyed, pyrothonide, quebonafide, quinagolide, repaglinide, rising tide, saint bride, saucer-eyed, semaglutide, server-side, sesquioxide, sleepy-eyed, slickenside, speechified, squint-eyed, starry-eyed, steely-eyed, strathclyde, succinimide, sulphionide, sunken-eyed, supply-side, swivel-eyed, syllabified, tetrahalide, thalidomide, tolbutamide, tongue-tied, trifluoride, tropicamide, trypanocide, twelfthtide, tyrannicide, unamplified, uncalcified, uncertified, unclarified, undignified, unfortified, ungratified, unjustified, unmortified, unqualified, unrectified, unsatisfied, unspecified, unterrified, unvitrified, vanderheide, vanderweide, verkoudheid, vonderheide, watery-eyed, whitsuntide, withanolide, yellow-eyed, al-mu'tadid, anomalipede, bella hadid, bottle-feed, breast-feed, camphorweed, canary seed, cancer weed, celery seed, certainteed, chickenfeed, common reed, cross-breed, double-reed, double reed, dragonspeed, edible seed, fennel seed, french weed, gracilariid, groundspeed, joel embiid, knack-kneed, knock-kneed, light speed, megatheriid, oliver reed, peyton reed, pumpkinseed, rabbit-weed, rattle weed, scratchweed, sesame seed, singlespeed, tettigoniid, thimbleweed, trumpetweed, tumble-weed, unpedigreed, vinegarweed, walter reed, willow-weed, winter-feed

12 letters:
acetaldehyde, andrew clyde, anisaldehyde, avunculicide, bacteriacide, bacteriocide, barium oxide, beenverified, benzaldehyde, benzthiazide, bicalutamide, biopesticide, borofluoride, carbodiimide, carbohydride, chalcogenide, copper oxide, corpse bride, country-wide, darolutamide, declassified, depsipeptide, diethylamide, dinucleotide, disaccharide, disglorified, disqualified, dissatisfied, districtwide, elamipretide, endoperoxide, enzalutamide, episcopicide, eptifibatide, ethosuximide, far and wide, fermaldahyde, fermaldehyde, fermaldihyde, ferricyanide, ferrocyanide, fluocinonide, formaldehyde, glutethimide, glycopeptide, great divide, heptapeptide, hexafluoride, hydrobromide, hydrocyanide, hydrosulfide, industrywide, iron carbide, leeward side, lenalidomide, lixisenatide, manderscheid, microbiocide, molluscicide, mountainside, neuropeptide, nifuroxazide, nitazoxanide, nitric oxide, nonqualified, oligopeptide, oversupplied, parasiticide, parentticide, pediculicide, pentapeptide, phensuximide, polyhexanide, polythiazide, pomalidomide, pre-verified, prucalopride, pseudohalide, radionuclide, reclassified, saccharified, scilliroside, sessile-eyed, side-by-side, side-to-side, side by side, spermatocide, sulfur oxide, temozolomide, teriparatide, tetrapeptide, tricarbimide, triglyceride, tryparsamide, unclassified, unidentified, unsanctified, unsaponified, unstratified, weather side, zangersheide, call-by-need, caraway seed, chicken feed, counterplead, crystal reed, devil's weed, english-weed, getyourguide, harris tweed, jumping seed, let it bleed, mustard seed, pickerelweed, polecat weed, prickle-weed, pumpkin seed, scorpionweed, star aniseed, trombiculiid, trumpet weed, unguaranteed

13 letters:
acetohexamide, acrylaldehyde, allhallowtide, ascensiontide, bistriflimide, boroglyceride, bremelanotide, bring outside, bufadienolide, butyraldehyde, calcium oxide, cambridgeside, chloroguanide, christmastide, communitywide, corporatewide, cuminaldehyde, cycloheximide, cyclothiazide, danny mcbride, dicyandiamide, furylfuramide, gene-modified, hydroperoxide, iodoacetamide, lantern slide, levosulpiride, miles mcbride, misclassified, misidentified, monoglyceride, monosaccaride, multiramified, nitroprusside, nitrous oxide, non-qualified, nonclassified, outsideinside, overqualified, park-and-ride, polyglycolide, presanctified, proxalutamide, pyruvaldehyde, retinaldehyde, self-homicide, semiacidified, semicarbazide, semivitrified, silicon oxide, silver iodide, sodium iodide, sulfacetamide, teriflunomide, tetrafluoride, thioacetamide, titanic oxide, transactinide, trinucleotide, trisaccharide, undersupplied, undiversified, unexemplified, vinyl cyanide, windward side, zircofluoride, at full speed, best-of-breed, false ragweed, great ragweed, jabesh-gilead, mohamed hadid, mortgage deed, pickerel weed, poke milkweed, pressure feed, ramoth-gilead, scorpion weed, silkworm seed, star-duckweed, stinking weed, yolanda hadid

14 letters:
4-anisaldehyde, aluminum oxide, aminoglycoside, barbados pride, barium dioxide, bendrofluazide, carbon dioxide, chlorothiazide, chlorpropamide, cinnamaldehyde, continent-wide, crotonaldehyde, dextromoramide, fibrinopeptide, furfuraldehyde, glutaraldehyde, glyceraldehyde, glycolaldehyde, graphite oxide, hydrated oxide, kirkbymoorside, methyl bromide, metoclopramide, michaela blyde, michaelmastide, michelin guide, mononucleotide, monosaccharide, mountain pride, murder-suicide, nibelungenlied, nitrogen oxide, novo-propamide, organoactinide, oversimplified, owner-occupied, platinocyanide, polyetherimide, polynucleotide, polysaccharide, ribonucleoside, ribonucleotide, self-satisfied, semilapidified, silver bromide, sodium cyanide, sodium hydride, stannofluoride, sulfur-dioxide, sulfur dioxide, tetracosactide, titanium oxide, transmogrified, trichomonacide, underqualified, well-qualified, westerwaldlied, alligator weed, balm of gilead, butterfly weed, common ragweed, coriander seed, fenugreek seed, great duckweed, jamestown weed, marsh milkweed, pineapple weed, safflower seed, showy milkweed, sunflower seed, swamp milkweed, taj-ul-masajid, water flaxseed, white milkweed

15 letters:
aluminium oxide, andrographolide, barium peroxide, board-certified, cadmium sulfide, calcium carbide, calcium hydride, deoxynucleotide, deuterium oxide, deutschlandlied, flurandrenolide, hildebrandslied, hydrogen iodide, interstratified, jekyll and hyde, magnesium oxide, malondialdehyde, melissa mcbride, oligonucleotide, oligosaccharide, on the far side, phenylacetamide, propionaldehyde, salicylaldehyde, silicon carbide, silicon dioxide, sodium fluoride, tetrasaccharide, uyghur genocide, zirconium oxide, apostles' creed, common duckweed, execution speed, house centipede, lesser duckweed, mead's milkweed, orange milkweed, poison milkweed, rheumatism weed, turpentine weed, western ragweed

16 letters:
akechi mitsuhide, argonnerwaldlied, assisted suicide, chlordiazepoxide, chlorine dioxide, cyclopenthiazide, cyclophosphamide, d-glyceraldehyde, diethyltoluamide, glucocerebroside, hilton worldwide, hydrogen bromide, hydrogen cyanide, hydrogen sulfide, hydroxycarbamide, michael ironside, nitrogen dioxide, paraformaldehyde, phosphoglyceride, phosphoinositide, potassium iodide, thiocolchicoside, titanium dioxide, assassin's creed, consumption weed, corn gluten feed, garden centipede, gulshan-e-hadeed, rattlesnake-weed, rattlesnake weed

17 letters:
aminoglutethimide, cardiac glucoside, cardiac glycoside, dideoxynucleotide, dimethylacetamide, dimethylformamide, dimethylsulfoxide, diphenylcarbazide, einheitsfrontlied, horst-wessel-lied, hydrogen fluoride, hydrogen peroxide, potassium bromide, potassium cyanide, trimethobenzamide, urea-formaldehyde, zirconium dioxide, perennial ragweed

18 letters:
apo-chlorpropamide, bromobenzylcyanide, cambodian genocide, continental divide, dihidrogenmonixide, dimethylsulphoxide, galactocerebroside, galactosylceramide, hydroflumethiazide, lipopolysaccharide, mucopolysaccharide, n-bromosuccinimide, phenylacetaldehyde, polyribonucleotide, trichlormethiazide, berwick-upon-tweed, frances shand kydd, horsetail milkweed

19 letters:
bendroflumethiazide, deoxyribonucleoside, deoxyribonucleotide, digitalis glycoside, hydrochlorothiazide, peach boy riverside, phenylthiocarbamide, xylooligosaccharide, egyptian paper reed, khalid ibn al-walid

20 letters:
dehydroretinaldehyde, hydroxyethylrutoside, n-hydroxysuccinimide, zinc cadmium sulfide, operation warp speed

21 letters:
fructooligosaccharide

22 letters:
galactooligosaccharide, polyvinyl-formaldehyde

23 letters:
hexamethylphosphoramide, isomaltooligosaccharide

24 letters:
1971 bangladesh genocide, syn-propanethial-s-oxide, the ancient magus' bride

26 letters:
paracetamol/metoclopramide

8 letters:
oxidized, oxidised

9 letters:
colonized

10 letters:
nonaligned, fossilized, apologized

11 letters:
compromised

13 letters:
flodden field