3 syllables:
clivity, privity

4 syllables:
acclivity, activity, captivity, clusivity, declivity, festivity, motivity, nativity, passivity, proclivity

5 syllables:
absorptivity, adaptivity, affectivity, aggressivity, agressivity, attractivity, coactivity, collectivity, conductivity, connectivity, corrosivity, creativity, deceptivity, destructivity, diffusivity, directivity, emissivity, ergativity, erosivity, exclusivity, exhaustivity, expansivity, expressivity, impassivity, impulsivity, inactivity, inclusivity, inductivity, infectivity, infestivity, instinctivity, intinctivity, negativity, normativity, objectivity, obsessivity, perceptivity, perfectivity, permittivity, perspectivity, proactivity, processivity, productivity, progressivity, projectivity, reactivity, receptivity, recessivity, recursivity, reflectivity, reflexivity, refractivity, regressivity, relativity, reluctivity, resistivity, responsivity, retentivity, selectivity, self-activity, sensitivity, sex activity, subjectivity, susceptivity, transitivity, transmissivity

6 syllables:
alternativity, bioactivity, business activity, commutativity, cooperativity, correlativity, cross-reactivity, generativity, human activity, hyperactivity, insensitivity, intempestivity, interactivity, interpassivity, intransitivity, overactivity, performativity, reproductivity, retroactivity, social activity, superactivity, underactivity, vasoactivity

7 syllables:
associativity, chemoreceptivity, chemosensitivity, commercial activity, evaporativity, impredicativity, incogitativity, intersubjectivity, offensive activity, oversensitivity, photoconductivity, pyroconductivity, radio-activity, radioactivity, regioselectivity, sensory activity, seronegativity, seropositivity, sexual activity, special relativity, subversive activity, superconductivity

8 syllables:
amatonormativity, anticommutativity, electroconductivity, electronegativity, general relativity, heteronormativity, immunoreactivity, intelligence activity, stereoselectivity, theory of relativity

9 syllables:
educational activity, enantioselectivity, human sexual activity

10 syllables:
extracurricular activity, special theory of relativity

11 syllables:
general theory of relativity

3 syllables:
civilly, cliquishly, critically, cryptically, cynically, dimity, fidgety, fishily, fittingly, gibingly, gimmickry, hillbilly, imagery, impishly, killingly, limpidly, lingeringly, mimicry, ministry, physically, pidlimdi, politically, principally, realty, rigidly, sickeningly, swimmingly, trinity, trippingly, typically, whimsically, wickedly, willingly, wittingly

4 syllables:
sensitively, admittedly, affinity, assiduity, auspiciously, avidity, befittingly, bewitchingly, capriciously, complicity, convincingly, cupidity, derisively, duplicity, ethnicity, exquisitely, facility, fertility, flaccidity, forgivingly, gentility, gracility, gravidity, humility, infinity, iniquity, intrinsically, judiciously, linguistically, liquidity, lividity, long-windedly, lucidity, mobility, motility, obliquity, pacifically, perniciously, placidity, publicity, sidesplittingly, simplicity, specifically, stability, statistically, sterility, stupidity, sublimity, submissively, terrifically, tonicity, tranquility, tranquillity, ubiquity, uncivilly, uncritically, unthinkingly, unwillingly, unwittingly, validity, vicinity, vindictively, virginity, viscidity

5 syllables:
competitively, affability, altruistically, anonymity, arability, atonicity, audibility, authenticity, avariciously, bendability, breakability, changeability, credibility, culpability, curability, disability, durability, edibility, egotistically, equanimity, fallibility, friability, gullibility, health facility, immobility, immotility, inability, inauspiciously, incivility, infertility, injudiciously, instability, liability, longanimity, magnanimity, meretriciously, movability, multiplicity, optimistically, palpability, pellucidity, pessimistically, plausibility, pliability, portability, provability, ratability, readability, realistically, scientifically, sensibility, serendipity, sociability, solubility, spinnability, squeezability, stainability, suitability, synchronicity, synonymity, taxability, tenability, tractability, unanimity, unconvincingly, unforgivingly, visibility, volubility

6 syllables:
accessibility, achievability, admirability, adorability, advisability, agreeability, alterability, amenability, answerability, assailability, attainability, availability, believability, characteristically, comparability, conceivability, convertibility, corruptibility, delectability, demonstrability, dependability, desirability, destructibility, discernability, dispensability, dissolubility, docking facility, eligibility, exchangeability, formidability, immovability, impalpability, impossibility, impregnability, inaudibility, incredibility, inculpability, incurability, indictability, infallibility, inflexibility, insolubility, intractability, invincibility, irascibility, manageability, maneuverability, marriageability, measurability, navigability, noticeability, penal facility, penetrability, perdurability, perfectability, perfectibility, permeability, permissibility, predictability, profitability, rateability, replaceability, respectability, separability, serviceability, sustainability, tax liability, transferability, transmutability, transposability, unchangeability, unrealistically, unsociability, variability, vulnerability

7 syllables:
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:
incomprehensibility, incontrovertibility, indefatigability, irreproducibility, limited liability

9 syllables:
recreational facility