3 syllables:
wallaby, colony, comradely, hostilely, broccoli, modesty, wannabe, possibly, rocketry, ology, 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

4 syllables:
monopsony, ontogeny, monotony, volubly, autonomy, pomology, cacophony, synonymy, astronomy, psephology, verbosity, technology, sinology, topography, horology, colostomy, conchology, mycology, misogamy, aerology, oncology, demography, geometry, zoology, homogeny, economy, monopoly, ecology, frivolity, garbology, doxology, tocology, neurology, philology, democracy, apostrophe, cytology, lithography, ontology, impolitely, anthology, pornography, comradery, thermometry, geology, geodesy, phonology, phytology, hypocrisy, nosology, demonstrably, orthography, ethnology, penology, gastronomy, atrocity, loquacity, velocity, misology, typography, ichthyology, agrology, trade policy, improbably, viscosity, impossibly, apostasy, moronity, comparably, proctology, equality, commodity, despondently, inconstancy, porosity, gibbosity, prodigally, impotency, pathology, philosophy, bureaucracy, planography, dishonesty, photography, theology, neology, virology, conjugally, apology, cartography, monstrosity, jocosity, unconsciously, ethology, serology, psychology, mammography, ethnography, mahogany, insolvency, allopathy, hydrometry, theocracy, phylogeny, tautology, optometry, morphology, agronomy, otology, astrometry, callosity, urology, histology, ferocity, hydrology, geography, mythology, despondency, chronology, posology, anomaly, biology, responsibly, allometry, biography, dichotomy, phrenology, low comedy, holography, astrology, enology, idolatry, spectrometry, homology, monogamy, seismology, autocracy, precocity, petrology, limnology, adamantly, adequacy, adequately, advocacy, allogamy, amphictyony, antiphony, antistrophe, appetency, canistel tree, casually, casualty, fashionably, fatuously, flatulency, laparoscopy, maximally, nationally, palatably, passionately, practicably, practically, rambutan tree, rationally, ravenously, salmagundi

5 syllables:
sinuosity, hematology, macrocephaly, archeology, anemometry, toxicology, aetiology, cardiography, angiology, actinometry, physiology, eschatology, teratology, rheumatology, anthropology, etymology, child psychology, uranology, true anomaly, dermatology, hagiology, volcanology, mineralogy, bibliography, depth psychology, audiometry, lexicography, haematology, ophthalmology, radiology, axiology, fiscal policy, primatology, inequality, scientology, embryology, adiposity, herpetology, gynaecology, parisology, roentgenography, tortuosity, etiology, high technology, jejunostomy, crystallography, aristocracy, foreign policy, ideology, tuberosity, egyptology, trigonometry, oenology, mediocrity, teleology, choreography, radiography, methodology, paleology, speleology, ideography, generosity, terminology, audiology, genealogy, cardiology, archaeology, sociology, poenology, animosity, entomology, immunology, criminology, curiosity, ornithology, climatology, adenopathy, irresponsibly, oceanography, anemography, hagiography, tracheostomy, lexicology, meniscectomy, sociometry, pharmacology, plane geometry, gerontology, numerosity, anthropometry, grandiosity, densitometry, anisogamy, gynecology, chromatography, anorthography, angiography, episiotomy, compassionately, extravagantly, grammatolatry, inadequately, inhabitancy, intransigency, irrationally, miraculously, peace advocacy, recalcitrancy, unanimously, unfashionably, unpalatably, war advocacy

6 syllables:
neuroanatomy, cardiomyopathy, antimonopoly, token economy, psychopathology, market economy, bacteriology, solid geometry, social democracy, autobiography, social psychology, musical comedy, endocrinology, human ecology, chromolithography, paleobotany, ultrasonography, escape velocity, religiosity, geomorphology, folk etymology, neuropsychology, meteorology, biotechnology, cinematography, parapsychology, glottochronology, offset lithography, palaeontology, epistemology, arteriography, neurobiology, insurance policy, paleontology, numismatology, applied psychology, telephotography, microbiology, moral philosophy, muzzle velocity, combat casualty, internationally, pusillanimity, pusillanimously

7 syllables:
projective geometry, natural theology, situation comedy, anesthesiology, psychopharmacology, physical geography, radio astronomy, clinical psychology, paper chromatography, terminal velocity, spherical geometry, african mahogany, paleopathology, epidemiology, bioclimatology, philippine mahogany, cognitive psychology, paleobiology, dynamic viscosity, social anthropology, psychophysiology, dialect geography, electromyography, column chromatography, paleornithology, natural philosophy, neurophysiology, doctor of philosophy, immunopathology, equipment casualty, personnel casualty

8 syllables:
cultural anthropology, micropaleontology, congenital anomaly, physical anthropology, comparative psychology, economic geography, paleoclimatology, molecular biology, proprietary colony, hyperbolic geometry, industrial psychology, paleoanthropology, analytic geometry, political economy

9 syllables:
coefficient of viscosity, developmental psychology, experimental psychology, operational casualty, unavoidable casualty

10 syllables:
physiological psychology