5 syllables:
amphibology

3 syllables:
wallaby, colony, comradely, hostilely, broccoli, modesty, wannabe, possibly, rocketry, quantity, novelty, policy, bodily, sodomy, botany, psalmody, homily, prodigy, sovereignty, monstrously, boloney, honesty, twopenny, audibly, frostily, honestly, constantly, quality, ptolemy, hostelry, bonhomie, comedy, dobsonfly, solidly, dovekie, commonly, potbelly, potently, romany, polony, constancy, monody, progeny, wantonly, modestly, consciously, gossipy, colloquy, crotchety, prosody, monandry, cobwebby, odyssey, prophecy, contrasty, probably, wobbly, wannabee, polity, oddity, conakry, boastfully, cogency, copiously, coquetry, dolefully, globally, hopefully, hopelessly, locally, momently, nobody, notably, openly, potency, probity, sociably, socially, totally, woefully, yeomanry

4 syllables:
monopsony, ontogeny, monotony, volubly, autonomy, cacophony, synonymy, astronomy, verbosity, topography, colostomy, misogamy, demography, geometry, homogeny, economy, monopoly, frivolity, democracy, apostrophe, lithography, impolitely, pornography, comradery, thermometry, geodesy, phonology, hypocrisy, demonstrably, orthography, gastronomy, atrocity, loquacity, velocity, typography, trade policy, improbably, viscosity, impossibly, apostasy, moronity, comparably, equality, commodity, despondently, inconstancy, porosity, spectroscopy, gibbosity, prodigally, impotency, philosophy, bureaucracy, planography, dishonesty, photography, conjugally, cartography, monstrosity, jocosity, unconsciously, mammography, ethnography, mahogany, insolvency, allopathy, hydrometry, theocracy, phylogeny, optometry, agronomy, astrometry, callosity, ferocity, geography, despondency, anomaly, responsibly, allometry, biography, dichotomy, fluoroscopy, low comedy, holography, idolatry, spectrometry, monogamy, autocracy, precocity, atrociously, diplomacy, emotionally, reproachfully, supposedly, unsociably

5 syllables:
sinuosity, laparoscopy, macrocephaly, anemometry, cardiography, actinometry, true anomaly, bibliography, audiometry, lexicography, fiscal policy, inequality, adiposity, roentgenography, stereoscopy, tortuosity, jejunostomy, crystallography, aristocracy, foreign policy, tuberosity, trigonometry, mediocrity, choreography, radiography, ideography, generosity, animosity, curiosity, adenopathy, irresponsibly, oceanography, anemography, hagiography, tracheostomy, meniscectomy, sociometry, plane geometry, numerosity, anthropometry, grandiosity, densitometry, anisogamy, chromatography, anorthography, angiography, episiotomy, irreproachably, ophiolatry, ponderosity, with diplomacy

6 syllables:
neuroanatomy, cardiomyopathy, antimonopoly, token economy, market economy, solid geometry, social democracy, autobiography, musical comedy, chromolithography, paleobotany, ultrasonography, escape velocity, religiosity, cinematography, offset lithography, arteriography, insurance policy, telephotography, moral philosophy, muzzle velocity, dollar diplomacy, gunboat diplomacy, without diplomacy

7 syllables:
projective geometry, situation comedy, physical geography, radio astronomy, paper chromatography, terminal velocity, spherical geometry, african mahogany, philippine mahogany, dynamic viscosity, dialect geography, electromyography, column chromatography, natural philosophy, doctor of philosophy

8 syllables:
congenital anomaly, economic geography, proprietary colony, hyperbolic geometry, analytic geometry, political economy

9 syllables:
coefficient of viscosity