3 syllables:
skillfully, visibly, timpani, symphony, synchrony, visually, tiffany, tinselly, whiffletree, infamy, flippancy, stringency, sympathy, viciously, wicopy, timothy, willowy, stickily, dimity, dittany, signally, wiggly, ministry, fixity, instantly, vividly, filigree, brilliancy, litany, spitefully, symmetry, trilogy, brilliantly, stingily, finicky, trinity, brittany, imagery, instancy, villainy, bigotry, dismally, industry, fiscally, wilfully, flippantly, bigamy, dingily, mistily, rickety, dignity, willfully, tripoli, whippletree, differently, finitely, timidly, minutely, sicily, swingletree, infancy, piquancy, italy, syncope, chivalry, infantry, giddily, dizzily, civilly, cliquishly, critically, cryptically, cynically, fishily, fittingly, gibingly, gimmickry, hillbilly, impishly, killingly, limpidly, lingeringly, mimicry, physically, pidlimdi, politically, principally, realty, rigidly, sickeningly, swimmingly, trippingly, typically, whimsically, wickedly, willingly, wittingly

4 syllables:
polygyny, proclivity, sufficiently, futility, viscidity, magistracy, benignancy, proficiency, facsimile, hostility, captivity, vicinity, gravimetry, torridity, indignity, salinity, antiquity, malignancy, publicity, invisibly, contingency, auspiciously, virility, utility, implicitly, solidity, resiliency, rigidity, liquidity, acidity, obstinately, rapidity, perniciously, tumidity, vapidity, aridity, astringency, toxicity, fluidity, humidity, timidity, turbidity, fragility, civility, antistrophe, ambitiously, affinity, antipathy, deficiency, spasticity, officially, cyclicity, initially, fertility, complicity, delinquency, sapidity, sweet cicely, asynchrony, polyphony, senility, deliciously, infinity, torpidity, epiphany, soliloquy, docility, ability, simplicity, religiously, flaccidity, abysmally, pasigraphy, miserably, polygamy, tepidity, proximity, avidity, growth industry, limpidity, felicity, antigone, sufficiency, explicitly, turgidity, festivity, placidity, literally, activity, immorally, consistently, liberally, tonicity, validity, mobility, prolixity, amphictyony, sphericity, culicidae, agility, somniloquy, viridity, nobility, ductility, asymmetry, consistency, propitiously, morbidity, efficiency, debility, divinity, nativity, epitome, efficiently, calligraphy, exigency, irritably, admittedly, assiduity, befittingly, bewitchingly, capriciously, convincingly, cupidity, derisively, duplicity, ethnicity, exquisitely, facility, forgivingly, gentility, gracility, gravidity, humility, iniquity, intrinsically, judiciously, linguistically, lividity, long-windedly, lucidity, motility, obliquity, pacifically, passivity, sidesplittingly, specifically, stability, statistically, sterility, stupidity, sublimity, submissively, terrifically, tranquility, tranquillity, ubiquity, uncivilly, uncritically, unthinkingly, unwillingly, unwittingly, vindictively, virginity

5 syllables:
intermittency, self-sufficiency, cucurbitaceae, alkalimetry, expeditiously, inauspiciously, exiguity, insufficiency, contractility, eccentricity, insufficiently, conditionally, relativity, creativity, unofficially, alkalinity, surreptitiously, masculinity, meretriciously, inefficiency, atonicity, originally, pellucidity, probability, supersymmetry, elasticity, domesticity, artificially, conductivity, injudiciously, volatility, holy trinity, deliberately, magnanimity, ellipticity, legibility, negativity, versatility, invalidity, infelicity, peripherally, catholicity, additionally, electricity, insipidity, intrepidity, femininity, inutility, calorimetry, feasibility, aborigine, inconsistency, chromaticity, unanimity, promiscuously, viability, fortuitously, traditionally, service industry, flexibility, possibility, productivity, irresistibly, inefficiently, unchristianly, specificity, avariciously, reactivity, colorimetry, capability, selectivity, affability, altruistically, anonymity, arability, audibility, authenticity, bendability, breakability, changeability, credibility, culpability, curability, directivity, disability, durability, edibility, effectivity, egotistically, equanimity, fallibility, friability, gullibility, health facility, immobility, immotility, impassivity, inability, inactivity, incivility, infertility, instability, liability, longanimity, movability, multiplicity, objectivity, obsessivity, optimistically, palpability, pessimistically, plausibility, pliability, portability, provability, ratability, readability, realistically, receptivity, reflexivity, scientifically, sensibility, sensitivity, serendipity, sociability, solubility, spinnability, squeezability, stainability, subjectivity, suitability, synchronicity, synonymity, taxability, tenability, tractability, unconvincingly, unforgivingly, visibility, volubility

6 syllables:
compatibility, radial symmetry, idiosyncrasy, invisibility, superciliously, susceptibility, reliability, individually, amiability, unequivocally, periodicity, muscular dystrophy, availability, chemical industry, malleability, apocynaceae, perfectibility, joint probability, acceptability, mental deficiency, neuropsychiatry, responsibility, public utility, applicability, pusillanimity, irritability, adaptability, palatability, unconditionally, admissibility, insensitivity, ignominiously, accessibility, achievability, admirability, adorability, advisability, agreeability, alterability, amenability, answerability, assailability, attainability, believability, characteristically, comparability, conceivability, convertibility, corruptibility, delectability, demonstrability, dependability, desirability, destructibility, discernability, dispensability, dissolubility, docking facility, eligibility, exchangeability, formidability, hyperactivity, immovability, impalpability, impossibility, impregnability, inaudibility, incredibility, inculpability, incurability, indictability, infallibility, inflexibility, insolubility, interactivity, intractability, invincibility, irascibility, manageability, maneuverability, marriageability, measurability, navigability, noticeability, overactivity, penal facility, penetrability, perdurability, perfectability, permeability, permissibility, predictability, profitability, rateability, replaceability, respectability, separability, serviceability, sustainability, tax liability, transferability, transmutability, transposability, unchangeability, unrealistically, unsociability, variability, vulnerability

7 syllables:
superconductivity, juvenile delinquency, inaccessibility, sexual activity, relative humidity, bioelectricity, bilateral symmetry, anthropocentricity, comprehensibility, hydroelectricity, irresponsibility, radioactivity, lactobacillaceae, static electricity, automobile industry, photoconductivity, special relativity, thermoelectricity, associability, athletic facility, companionability, impenetrability, imperfectibility, impermeability, impermissibility, inadvisability, incompatibility, inconceivability, incorruptibility, indestructibility, indispensability, indomitability, indubitability, inevitability, inexorability, interchangeability, invariability, invulnerability, manipulability, quantifiability, reproducibility, unalterability, unavailability, uncharacteristically, undependability, understandability, undesirability, unexchangeability, unmalleability, unpredictability, unprofitability, unquestionability, unreliability, unrespectability

8 syllables:
theory of relativity, general relativity, piezoelectricity, incomprehensibility, incontrovertibility, indefatigability, irreproducibility, limited liability

9 syllables:
atmospheric electricity, recreational facility