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, fidgety, instantly, vividly, filigree, brilliancy, litany, spitefully, symmetry, trilogy, brilliantly, stingily, finicky, trinity, brittany, imagery, instancy, villainy, bigotry, dismally, 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, bishopry, chintzily, filthily, flindosy, frigidly, hymnody, licitly, lingually, millime, minstrelsy, prissily, quizzically, ribbony, simile, skilfully, stringently, trickily, twinkly, viscidly, windily, winsomely, wriggly

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, asynchrony, polyphony, senility, deliciously, infinity, torpidity, epiphany, soliloquy, docility, ability, simplicity, religiously, flaccidity, abysmally, pasigraphy, miserably, polygamy, tepidity, proximity, avidity, 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, acclivity, acridity, declivity, forgivably, gelidity, insistency, malignity, mendicancy, motivity, permissibly, persistency, persnickety, plasticity, propinquity, rusticity, sanguinity, stolidity, tactility, unthinkably, ventriloquy

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, 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, flexibility, possibility, productivity, irresistibly, inefficiently, unchristianly, specificity, avariciously, reactivity, colorimetry, capability, selectivity, absorptivity, chondrodystrophy, concentricity, consanguinity, expansivity, imbecility, impermissibly, inconsistently, inhospitably, mutability, notability, perceptivity, progressivity, quotability, reflectivity, refractivity, reluctivity, resistivity, retentivity, risibility, stretchability, syllabicity, tangibility, transitivity, unambitiously, unforgivably, unpredictably, unpropitiously

6 syllables:
compatibility, idiosyncrasy, invisibility, superciliously, susceptibility, reliability, individually, amiability, unequivocally, periodicity, availability, malleability, apocynaceae, perfectibility, acceptability, neuropsychiatry, responsibility, applicability, pusillanimity, irritability, adaptability, palatability, unconditionally, admissibility, insensitivity, ignominiously, amicability, analyticity, antifertility, approachability, commutability, compressibility, contemptibility, correlativity, deductibility, despicability, digestibility, duplicability, equatability, excitability, higgledy-piggledy, illegibility, immutability, impeachability, implausibility, improbability, incapability, inelasticity, infeasibility, inscrutability, insensibility, intangibility, intransitivity, perceptibility, permutability, practicability, reputability, reversibility, semifluidity, suggestibility, unfeasibility, unsuitability

7 syllables:
superconductivity, inaccessibility, bioelectricity, anthropocentricity, comprehensibility, hydroelectricity, irresponsibility, radioactivity, lactobacillaceae, photoconductivity, thermoelectricity, disreputability, imperceptibility, imperishability, imperturbability, impracticability, inadmissibility, inapplicability, incommutability, incompressibility, inconvertibility, indigestibility, indisputability, ineligibility, intelligibility, irrepressibility, irreversibility, reprehensibility, substitutability, unacceptability, unadaptability, unapproachability, unpalatability, unsusceptibility

8 syllables:
piezoelectricity, indistinguishability, unintelligibility