1 syllable:
-backed, achte, act, backed, blacked, bracht, brachte, bract, clacked, cracked, dachte, fact, flacked, fracht, fract, gackt, gracht, hacked, jacht, jacked, knacked, kracht, lacked, lact-, nackt, pacht, packed, packt, pact, pacte, pracht, quacked, qvacked, racked, rakht, sacked, schacht, schlacht, shacked, slacked, smacked, snacked, stacked, stacte, tacked, tact, takht, tracht, trachte, tracked, tract, trakt, wacked, whacked, wracked, yacked, yakked, zacht

2 syllables:
abstract, adact, air-slacked, anact, attacked, attract, auftakt, backpacked, backtracked, barebacked, betracht, blackjacked, bunch-backed, bushwhacked, car-jacked, carjacked, cei-pact, cextract, close-packed, coact, compact, confract, contact, contract, crookbacked, deact, detract, didact, diffract, distract, eintracht, en-tact, enact, entracte, epact, ex'act, exact, exakt, extract, fast-tracked, finchbacked, galact, galact-, gebracht, gedacht, gedact, genpact, gobsmacked, half-cracked, half-tracked, hardbacked, high-backed, highjacked, hijacked, humpbacked, hunchbacked, impact, infract, intact, in fact, jam-packed, jampacked, kompakt, kontakt, kontakte, low-backed, lute-backed, medfact, mossbacked, nerve tract, olfact, one-act, outact, peract, play-act, playact, postact, postfact, preact, prepacked, protract, ransacked, re-act, react, redact, refract, repacked, retract, roach-backed, rofact, rollbacked, round-backed, sanakht, sex act, sidetracked, skyjacked, speech act, stiff-backed, straight-backed, subact, substract, subtract, sway-backed, swaybacked, switchbacked, tarmacked, thumbtacked, tocktact, transact, unbacked, unfact, unhacked, unpacked, unslacked, untracked, vkontakte, well-stacked, wisecracked

3 syllables:
abreact, acetract, action-packed, anteact, antefact, artefact, asset-backed, autofact, benefact, biofact, broken-backed, camel-backed, cataphract, cateract, chain-react, contrafact, counteract, cross-react, ecofact, edifact, eye contact, fly contact, fraud in fact, full-contact, fullcontact, geofact, high-impact, huckle-backed, imfact, incoact, inexact, interact, ladder-backed, lobster-backed, medivaced, medivacked, mortgage-backed, non-contract, noncontract, optic tract, overact, paperbacked, piggybacked, pontefract, precontact, precontract, quarterbacked, razor-backed, re-enact, recontact, reenact, retroact, retrofract, riot act, rotaract, saddle-backed, saddlebacked, shadowpact, sister act, smart contract, special act, spiny-backed, spiritpact, subcontract, tadelakt, tesseract, underact, unexact, vacuum-packed, ventifact

4 syllables:
accomplished fact, almond extract, autodidact, bataireacht, breach of contract, cola extract, counterattacked, digestive tract, enviropact, finding of fact, fluidextract, futures contract, gabriel macht, genshin impact, in point of fact, labor contract, lemon extract, marriage contract, matter-of-fact, matter of fact, oral contract, output contract, overreact, politifact, purchase contract, quasi-contract, quasi contract, question of fact, semi-abstract, semiabstract, semicompact, service contract, social contract, special contract, suicide pact, underreact

5 syllables:
attorney-in-fact, caterpillar-tracked, contrary to fact, employment contract, enabling act, gambling contract, legislative act, requirements contract, term of a contract, urinary tract, vanilla extract

6 syllables:
affordable care act, alimentary tract, as a matter of fact, bilateral contract, conditional contract, create by mental act, electrical contact, respiratory tract

7 syllables:
aleatory contract, gastrointestinal tract, unilateral contract

8 syllables:
accessory after the fact, accessory before the fact

10 syllables:
occupational safety and health act

3 syllables:
thermostat, fore-topmast, cormous plant