5 letters:
istic

6 letters:
-istic, bistek, bistik, cistic, cystic, fistic, mistic, mystic, pistic, sistek

7 letters:
crystic, deistic, eristic, swistak

8 letters:
aoristic, artistic, autistic, christic, egoistic, holistic, juristic, logistic, meristic, miss tic, monistic, myristic, nomistic, papistic, poristic, puristic, sadistic, schistic, sufistic, theistic, tristich, truistic, veristic, yogistic

9 letters:
aeolistic, agonistic, ameristic, amoristic, animistic, atheistic, atomistic, ballistic, baptistic, casuistic, choristic, cladistic, czaristic, dereistic, diaristic, dioristic, dualistic, egotistic, elohistic, faunistic, fideistic, heuristic, hubristic, imagistic, judaistic, leucistic, mantistic, meroistic, oligistic, onanistic, panoistic, patristic, pietistic, realistic, sophistic, statistic, statistik, stylistic, thomistic, tsaristic, wholistic, yahwistic, zionistic

10 letters:
albinistic, altruistic, annalistic, aphoristic, cabalistic, canonistic, coloristic, ditheistic, docetistic, donatistic, dynamistic, empiristic, erethistic, eulogistic, euphuistic, familistic, fatalistic, feministic, futuristic, hedonistic, humanistic, humoristic, idealistic, inartistic, jehovistic, jingoistic, latinistic, legalistic, linguistic, melanistic, monocystic, moralistic, nativistic, naturistic, nepotistic, nihilistic, novelistic, optimistic, paeanistic, paracystic, pericystic, phlogistic, pilocystic, polaristic, polycystic, pugilistic, qabalistic, quietistic, rigoristic, romanistic, sciolistic, simplistic, solecistic, tokenistic, totalistic, totemistic, unartistic, unionistic, urbanistic, vitalistic

11 letters:
alchemistic, alchymistic, animalistic, animatistic, anomalistic, aphlogistic, aprioristic, atomatistic, atonalistic, biologistic, cabbalistic, caesaristic, calvinistic, cholecystic, citharistic, communistic, curialistic, darwinistic, dialogistic, dislogistic, duopolistic, dyslogistic, epilogistic, erythristic, eucharistic, euphemistic, extracystic, fetichistic, feudalistic, fibrocystic, formulistic, harmonistic, hellenistic, intracystic, jargonistic, kabbalistic, mechanistic, mediumistic, melioristic, mentalistic, modernistic, mutualistic, narcicistic, neologistic, nontheistic, oligocystic, pantheistic, pessimistic, pilpulistic, platonistic, pluralistic, racialistic, ritualistic, shamanistic, socialistic, sphragistic, spinozistic, spiritistic, stalinistic, syllogistic, symbolistic, synergistic, t-statistic, talmudistic, terroristic, tribadistic, tribalistic, tritheistic, u-statistic, unrealistic, vandalistic, verbalistic, violinistic, voodooistic, voyeuristic

12 letters:
absolutistic, anabaptistic, antagonistic, avifaunistic, belletristic, belletristik, bolshevistic, cameralistic, capitalistic, centralistic, chauvanistic, chauvinistic, chrematistic, concretistic, dysphemistic, eudemonistic, euhemeristic, folkloristic, gradualistic, henotheistic, hinayanistic, hypocoristic, illuministic, journalistic, liberalistic, literalistic, mahayanistic, militaristic, minimalistic, monopolistic, monotheistic, narcissistic, naturalistic, negativistic, nematocystic, neutralistic, nominalistic, nonrealistic, paleocrystic, phenocrystic, plagiaristic, polytheistic, positivistic, pragmatistic, recidivistic, relativistic, reunionistic, revivalistic, secularistic, sensualistic, separatistic, specialistic, surrealistic, syncretistic, theochristic, trichocystic

13 letters:
adiaphoristic, anachronistic, antiballistic, behavioristic, bimetallistic, cannibalistic, colonialistic, communalistic, deterministic, diachronistic, equilibristic, eudaemonistic, externalistic, formularistic, illusionistic, imperialistic, materialistic, maternalistic, metaheuristic, monopsonistic, nationalistic, nonlinguistic, objectivistic, oligopolistic, opportunistic, panentheistic, parallelistic, paternalistic, personalistic, physicalistic, pointillistic, primitivistic, probabilistic, rationalistic, regionalistic, synchronistic, syndicalistic, voluntaristic

14 letters:
abdominocystic, acephalocystic, antiphlogistic, behaviouristic, bibliopegistic, bibliopolistic, characteristic, collectivistic, emotionalistic, evolutionistic, expansionistic, filiopietistic, hyperrealistic, intuitionistic, isolationistic, megalopolistic, mercantilistic, metalinguistic, nonmechanistic, overoptimistic, parachronistic, paralinguistic, philosophistic, photorealistic, propagandistic, psychologistic, reductionistic, somnambulistic, spiritualistic, subjectivistic, universalistic

15 letters:
bibliophilistic, commercialistic, conceptualistic, contortionistic, ethnolinguistic, exhibitionistic, expressionistic, extralinguistic, feuilletonistic, impressionistic, indeterministic, individualistic, intralinguistic, lexicostatistic, neurolinguistic, nonrelativistic, oligolopolistic, particularistic, perfectionistic, phenomenalistic, progressivistic, sociolinguistic, ventriloquistic

16 letters:
associationistic, cross-linguistic, fundamentalistic, nondeterministic, obstructionistic, psycholinguistic, religious mystic, sensationalistic, traditionalistic, ultramodernistic, uncharacteristic

17 letters:
electro-ballistic, intellectualistic, non-deterministic, photojournalistic, supernaturalistic, supranaturalistic

18 letters:
internationalistic, sex characteristic, ultranationalistic

20 letters:
parametric statistic, supercalifragilistic

26 letters:
primary sex characteristic

27 letters:
distribution free statistic

28 letters:
secondary sex characteristic

6 letters:
biskek