5 letters:
ology

6 letters:
oology

7 letters:
acology, apology, biology, ecology, enology, geology, myology, neology, orology, otology, urology, zoology

8 letters:
aerology, agrology, algology, axiology, bryology, cacology, cetology, cytology, doxology, ethology, etiology, fetology, homology, horology, ideology, menology, misology, mycology, nomology, nosology, oenology, oncology, ontology, pedology, penology, pomology, posology, rheology, serology, sexology, sinology, sitology, theology, tocology, topology, typology, virology, zymology

9 letters:
acarology, adenology, aetiology, agriology, anemology, angiology, anthology, astrology, audiology, battology, carpology, chirology, coprology, cosmology, desmology, ethnology, etymology, garbology, genealogy, hagiology, haplology, hierology, histology, hydrology, hymnology, hypnology, ichnology, iconology, iridology, limnology, lithology, macrology, mammalogy, metrology, micrology, museology, mythology, necrology, nephology, neurology, ophiology, osteology, paleology, pathology, patrology, petrology, phenology, philology, phycology, phytology, poenology, radiology, rhinology, sarcology, scatology, semiology, sociology, symbology, tautology, tetralogy, tribology, tropology, uranology

10 letters:
actinology, angelology, archeology, aristology, arthrology, autecology, balneology, bibliology, brontology, cardiology, carphology, chronology, conchology, craniology, cryptology, deltiology, demonology, dendrology, deontology, egyptology, embryology, entomology, enzymology, escapology, exobiology, futurology, gastrology, glaciology, glossology, graphology, gynecology, hematology, hepatology, heterology, immunology, lexicology, malacology, mineralogy, morphology, musicology, nephrology, numerology, oceanology, odontology, organology, orismology, palaeology, palynology, parisology, phlebology, phrenology, physiology, proctology, psephology, pseudology, seismology, selenology, somatology, speleology, sumerology, synecology, technology, teratology, toxicology, trichology

11 letters:
aerobiology, agrobiology, agrostology, alethiology, allergology, arachnology, archaeology, assyriology, bromatology, campanology, christology, climatology, cosmetology, criminology, cryobiology, dactylology, dermatology, eschatology, fossilology, gerontology, gynaecology, haematology, herpetology, ichthyology, kinesiology, laryngology, lichenology, martyrology, meteorology, methodology, myrmecology, neonatology, onomatology, ornithology, paletiology, planetology, primatology, pteridology, reflexology, scientology, semasiology, soteriology, spelaeology, stomatology, suicidology, terminology, thanatology, venereology, vexillology, volcanology, vulcanology

12 letters:
anthropology, astrobiology, bacteriology, dialectology, dysteleology, ecclesiology, enigmatology, epidemiology, epistemology, hydrogeology, liturgiology, microbiology, neurobiology, palaetiology, paleobiology, paleoecology, paleogeology, paleontology, paleozoology, parasitology, pathobiology, perinatology, pharmacology, photobiology, pneumatology, protozoology, radiobiology, rheumatology, sociobiology, stoichiology, traumatology

13 letters:
biotechnology, chronobiology, cryptozoology, endocrinology, geochronology, geomorphology, helminthology, human ecology, numismatology, ophthalmology, palaeobiology, palaeogeology, palaeontology, palaeozoology, psychobiology, roentgenology, sedimentology, splanchnology

14 letters:
anesthesiology, bioclimatology, biometeorology, folk etymology, histopathology, mining geology, neuropathology, otolaryngology, paleomammalogy, paleopathology, parapsychology, phytopathology, symptomatology

15 letters:
anaesthesiology, ethnomusicology, greek mythology, high technology, immunopathology, neurophysiology, neuropsychology, norse mythology, palaeopathology, paleodendrology, paleornithology, pathophysiology, protoarcheology, psychopathology, rail technology, roman mythology

16 letters:
dendrochronology, economic geology, gastroenterology, glottochronology, hydrometeorology, natural theology, palaeodendrology, palaeornithology, paleoclimatology, protoarchaeology, psychophysiology

17 letters:
electrophysiology, marine archeology, micropaleontology, molecular biology, neuropharmacology, palaeoclimatology, paleoanthropology, petroleum geology, protoanthropology

18 letters:
christian theology, clinical neurology, doctor of theology, human paleontology, marine archaeology, master of theology, neuroendocrinology, psychopharmacology

19 letters:
classical mythology, compound morphology, computer technology, otorhinolaryngology, social anthropology

20 letters:
bachelor of theology

21 letters:
automotive technology, cultural anthropology, department of biology, physical anthropology, psychoneuroimmunology, underwater archeology

22 letters:
underwater archaeology

23 letters:
department of sociology

24 letters:
descriptive anthropology

25 letters:
communications technology

26 letters:
department of anthropology

33 letters:
digital communications technology

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

7 letters:
wallaby, volubly, modesty, wannabe, novelty, economy, prodigy, boloney, honesty, geodesy, audibly, quality, ptolemy, solidly, dovekie, progeny, gossipy, prosody, odyssey, anomaly, conakry, apogamy, balmily, biogeny, dottily, exogamy, isogamy, knobbly, obloquy, rommany, talkily

8 letters:
ontogeny, monotony, autonomy, broccoli, synonymy, possibly, rocketry, misogamy, geometry, quantity, homogeny, monopoly, psalmody, twopenny, atrocity, velocity, frostily, honestly, apostasy, hostelry, moronity, bonhomie, equality, porosity, commonly, potbelly, potently, wantonly, jocosity, modestly, colloquy, mahogany, monandry, cobwebby, agronomy, prophecy, probably, ferocity, wannabee, idolatry, monogamy, autogeny, blossomy, caudally, connally, isometry, promisee, prophesy, rottenly, stodgily, zoolatry

9 letters:
monopsony, sinuosity, comradely, hostilely, cacophony, astronomy, verbosity, colostomy, frivolity, democracy, comradery, phonology, hypocrisy, loquacity, adiposity, viscosity, dobsonfly, commodity, gibbosity, impotency, constancy, crotchety, animosity, allopathy, theocracy, curiosity, phylogeny, optometry, contrasty, callosity, geography, allometry, biography, dichotomy, anisogamy, autocracy, precocity, algometry, allotropy, androgeny, globosity, idiolatry, immodesty, lithotomy, monocracy, noxiously, pyrolatry, squalidly, theosophy, topolatry, tuatha de

10 letters:
anemometry, topography, demography, apostrophe, audiometry, impolitely, inequality, gastronomy, typography, tortuosity, improbably, constantly, impossibly, tuberosity, comparably, mediocrity, prodigally, philosophy, dishonesty, ideography, conjugally, generosity, insolvency, hydrometry, adenopathy, astrometry, sociometry, numerosity, low comedy, holography, episiotomy, astrolatry, bardolatry, bottletree, cacography, celioscopy, cosmolatry, diabolatry, gymnosophy, gyneolatry, hagiolatry, heliolatry, iconolatry, immodestly, laparotomy, lordolatry, naprapathy, old colony, plutocracy, preciosity, radioscopy, sonography, symbolatry, tax policy, venography, verbolatry, viscometry, watchfully, xerography

11 letters:
laparoscopy, actinometry, sovereignty, lithography, monstrously, pornography, thermometry, orthography, paleobotany, religiosity, stereoscopy, jejunostomy, aristocracy, inconstancy, radiography, bureaucracy, planography, photography, cartography, monstrosity, consciously, mammography, ethnography, anemography, hagiography, despondency, responsibly, fluoroscopy, grandiosity, angiography, arborolatry, arthroscopy, bibliolatry, bonduc tree, cosmography, demonolatry, glutinosity, gynaeolatry, hydrography, low quality, obnoxiously, paleography, psychometry, seriocomedy, top-quality, tragicomedy

12 letters:
neuroanatomy, macrocephaly, antimonopoly, cardiography, true anomaly, bibliography, lexicography, demonstrably, trade policy, trigonometry, despondently, spectroscopy, choreography, oceanography, tracheostomy, meniscectomy, densitometry, spectrometry, arthrography, biogeography, farce comedy, glyptography, high quality, palaeobotany, passamaquody, physiography, symbololatry, voluminosity, with modesty

13 letters:
token economy, autobiography, fiscal policy, unconsciously, arteriography, irresponsibly, anthropometry, anorthography, anthropolatry, calabash tree, child prodigy, guenon monkey, hypervelocity, social policy, thaumatolatry, true mahogany

14 letters:
cardiomyopathy, market economy, solid geometry, musical comedy, foreign policy, cinematography, plane geometry, chromatography, cedar mahogany, cholelithotomy, cuban mahogany, defence policy, defense policy, disconsolately, paleogeography, prime quantity, size constancy

15 letters:
radio astronomy, ultrasonography, escape velocity, roentgenography, crystallography, telephotography, muzzle velocity, cholangiography, color constancy, economic policy, floating policy, managed economy, palaeogeography, shape constancy, without modesty

16 letters:
situation comedy, social democracy, african mahogany, electromyography, insurance policy, moral philosophy, complex quantity, legal philosophy, maternal quality, news photography, paleoethnography, parental quality, paternal quality, photolithography, self-consciously, unknown quantity

17 letters:
terminal velocity, chromolithography, dynamic viscosity, dialect geography, analytic geometry, political economy, communist economy, constant quantity, definite quantity, honduras mahogany, mammothermography, mass spectroscopy, palaeoethnography, relative quantity, socialist economy, unit of viscosity, unselfconsciously, variable quantity

18 letters:
congenital anomaly, physical geography, economic geography, spherical geometry, proprietary colony, offset lithography, natural philosophy, absolute viscosity, capitalist economy, decline in quality, dominican mahogany, numerical quantity, parabolic geometry, powder photography

19 letters:
projective geometry, philippine mahogany, hyperbolic geometry, analytical geometry, coordinate geometry, doctor of optometry, elementary geometry, indefinite quantity, parametric quantity

20 letters:
paper chromatography, doctor of philosophy, brightness constancy, descriptive geometry, linguistic geography

21 letters:
column chromatography, empiricist philosophy

23 letters:
national trading policy, parliamentary democracy

24 letters:
coefficient of viscosity, african scented mahogany, department of philosophy

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

31 letters:
council on environmental policy