5 letters:
ology

6 letters:
colony, policy, bodily, sodomy, botany, homily, comedy, romany, polony, monody, wobbly, polity, oddity, cosily, cozily, foxily

7 letters:
wallaby, volubly, modesty, wannabe, zoology, novelty, economy, ecology, prodigy, boloney, honesty, geology, geodesy, audibly, quality, ptolemy, solidly, dovekie, neology, apology, progeny, gossipy, prosody, odyssey, otology, urology, anomaly, biology, enology, conakry, apogamy, balmily, biogeny, dottily, exogamy, isogamy, knobbly, obloquy, rommany, talkily

8 letters:
ontogeny, monotony, autonomy, pomology, broccoli, synonymy, possibly, rocketry, sinology, horology, mycology, misogamy, aerology, oncology, geometry, quantity, homogeny, monopoly, doxology, tocology, psalmody, cytology, ontology, axiology, twopenny, nosology, penology, atrocity, velocity, frostily, misology, agrology, honestly, etiology, apostasy, ideology, hostelry, moronity, bonhomie, equality, oenology, porosity, commonly, potbelly, potently, theology, virology, wantonly, jocosity, ethology, modestly, serology, colloquy, mahogany, monandry, cobwebby, agronomy, prophecy, probably, ferocity, posology, wannabee, idolatry, homology, monogamy, autogeny, blossomy, caudally, connally, isometry, promisee, prophesy, rottenly, stodgily, zoolatry

9 letters:
monopsony, sinuosity, comradely, hostilely, cacophony, astronomy, aetiology, verbosity, angiology, colostomy, etymology, frivolity, uranology, garbology, hagiology, neurology, philology, democracy, radiology, anthology, comradery, phonology, phytology, hypocrisy, ethnology, loquacity, adiposity, viscosity, dobsonfly, commodity, gibbosity, teleology, impotency, pathology, paleology, constancy, audiology, genealogy, sociology, poenology, crotchety, animosity, allopathy, theocracy, curiosity, phylogeny, tautology, optometry, contrasty, callosity, histology, hydrology, mythology, allometry, dichotomy, astrology, anisogamy, autocracy, precocity, petrology, limnology, algometry, allotropy, androgeny, globosity, idiolatry, immodesty, lithotomy, mammalogy, monocracy, noxiously, pyrolatry, squalidly, tetralogy, theosophy, topolatry, tuatha de

10 letters:
hematology, archeology, anemometry, toxicology, psephology, technology, conchology, physiology, teratology, mineralogy, apostrophe, audiometry, impolitely, inequality, embryology, gastronomy, parisology, tortuosity, improbably, constantly, impossibly, tuberosity, comparably, proctology, egyptology, mediocrity, prodigally, philosophy, dishonesty, speleology, conjugally, generosity, cardiology, psychology, insolvency, entomology, immunology, hydrometry, morphology, adenopathy, lexicology, astrometry, sociometry, chronology, numerosity, phrenology, low comedy, seismology, gynecology, episiotomy, astrolatry, bardolatry, bottletree, celioscopy, cosmolatry, diabolatry, gymnosophy, gyneolatry, hagiolatry, heliolatry, iconolatry, immodestly, laparotomy, lordolatry, naprapathy, old colony, palaeology, plutocracy, preciosity, radioscopy, sumerology, symbolatry, tax policy, verbolatry, viscometry, watchfully

11 letters:
laparoscopy, actinometry, eschatology, dermatology, volcanology, sovereignty, monstrously, haematology, thermometry, primatology, scientology, paleobotany, ichthyology, herpetology, gynaecology, religiosity, stereoscopy, jejunostomy, aristocracy, meteorology, inconstancy, methodology, bureaucracy, terminology, monstrosity, archaeology, consciously, criminology, ornithology, climatology, despondency, gerontology, responsibly, fluoroscopy, grandiosity, agrobiology, arborolatry, arthroscopy, assyriology, bibliolatry, bonduc tree, demonolatry, glutinosity, gynaeolatry, low quality, obnoxiously, paletiology, psychometry, seriocomedy, spelaeology, top-quality, tragicomedy

12 letters:
neuroanatomy, macrocephaly, antimonopoly, bacteriology, rheumatology, anthropology, true anomaly, epidemiology, demonstrably, trade policy, paleobiology, trigonometry, despondently, spectroscopy, epistemology, neurobiology, tracheostomy, paleontology, meniscectomy, pharmacology, microbiology, densitometry, spectrometry, farce comedy, high quality, palaeobotany, palaetiology, paleogeology, paleozoology, passamaquody, protozoology, sociobiology, symbololatry, voluminosity, with modesty

13 letters:
token economy, ophthalmology, endocrinology, fiscal policy, human ecology, geomorphology, biotechnology, unconsciously, palaeontology, irresponsibly, numismatology, anthropometry, anthropolatry, calabash tree, child prodigy, guenon monkey, hypervelocity, palaeobiology, palaeogeology, palaeozoology, social policy, thaumatolatry, true mahogany

14 letters:
cardiomyopathy, market economy, solid geometry, anesthesiology, musical comedy, paleopathology, bioclimatology, foreign policy, folk etymology, parapsychology, plane geometry, cedar mahogany, cholelithotomy, cuban mahogany, defence policy, defense policy, disconsolately, mining geology, paleomammalogy, prime quantity, size constancy

15 letters:
psychopathology, radio astronomy, escape velocity, high technology, neuropsychology, paleornithology, neurophysiology, immunopathology, muzzle velocity, color constancy, economic policy, floating policy, greek mythology, managed economy, norse mythology, palaeopathology, paleodendrology, protoarcheology, rail technology, roman mythology, shape constancy, without modesty

16 letters:
natural theology, situation comedy, child psychology, social democracy, depth psychology, paleoclimatology, african mahogany, psychophysiology, glottochronology, insurance policy, moral philosophy, complex quantity, economic geology, legal philosophy, maternal quality, palaeodendrology, palaeornithology, parental quality, paternal quality, protoarchaeology, self-consciously, unknown quantity

17 letters:
micropaleontology, social psychology, terminal velocity, molecular biology, dynamic viscosity, paleoanthropology, analytic geometry, political economy, animal psychology, communist economy, constant quantity, definite quantity, honduras mahogany, marine archeology, mass spectroscopy, palaeoclimatology, petroleum geology, protoanthropology, relative quantity, socialist economy, unit of viscosity, unselfconsciously, variable quantity

18 letters:
psychopharmacology, congenital anomaly, spherical geometry, proprietary colony, applied psychology, natural philosophy, absolute viscosity, capitalist economy, christian theology, clinical neurology, decline in quality, doctor of theology, dominican mahogany, genetic psychology, human paleontology, marine archaeology, master of theology, numerical quantity, parabolic geometry

19 letters:
projective geometry, clinical psychology, philippine mahogany, hyperbolic geometry, social anthropology, analytical geometry, classical mythology, compound morphology, computer technology, coordinate geometry, doctor of optometry, elementary geometry, indefinite quantity, parametric quantity

20 letters:
cognitive psychology, doctor of philosophy, bachelor of theology, brightness constancy, descriptive geometry

21 letters:
cultural anthropology, physical anthropology, industrial psychology, automotive technology, department of biology, empiricist philosophy, underwater archeology

22 letters:
comparative psychology, underwater archaeology

23 letters:
experimental psychology, department of sociology, differential psychology, national trading policy, parliamentary democracy

24 letters:
physiological psychology, coefficient of viscosity, developmental psychology, african scented mahogany, department of philosophy, department of psychology, descriptive anthropology

25 letters:
communications technology, large indefinite quantity, small indefinite quantity, transcendental philosophy

26 letters:
department of anthropology

31 letters:
council on environmental policy

33 letters:
digital communications technology