3 syllables:
ephesian, etesian, teresian

4 syllables:
o'hanesian, ohanesian, rabelaisian

5 syllables:
ferromagnesian

2 syllables:
pleven, treason, heathen, steven, grecian, stephen, season, reason, khoisan, caisson, cession, cresson, deafen, devon, essen, evan, freshen, heaven, hessian, leaven, lessen, lesson, question, resin, session, seven, stetson

3 syllables:
accretion, completion, depletion, preseason, phoenician, repletion, secretion, high treason, phaethon, excretion, uneven, deletion, unreason, dry season, venetian, concretion, accession, aggression, bull session, closed session, compression, concession, confession, dance lesson, depression, digression, discretion, egression, eleven, expression, french lesson, golf lesson, gum resin, impression, jam session, obsession, oppression, possession, precession, procession, profession, progression, rap session, recession, refreshen, regression, repression, secession, skull session, succession, suppression, transgression

4 syllables:
age of reason, rainy season, silly season, permeation, growing season, deaccession, decompression, dispossession, german lesson, great depression, health profession, hebrew lesson, indiscretion, intercession, language lesson, learned profession, music lesson, nonaggression, object lesson, practice session, prepossession, repossession, retrogression, self-expression, self-possession, sense impression, seventh heaven, special session, supersession, tennis lesson, tree of heaven, twenty-seven, vault of heaven, vinyl resin, wage concession

5 syllables:
elizabethan, acrylic resin, amino resin, cannabis resin, delicatessen, epoxy resin, facial expression, history lesson, image compression, legal profession, line of succession, manic depression, manna from heaven, melamine resin, natural resin, phenolic resin, piano lesson, silicone resin, simple regression, synthetic resin, taking possession, transferred possession, violin lesson, without expression

6 syllables:
mispronunciation, clinical depression, executive session, harmonic progression, immunosuppression, indirect expression, linear regression, medical profession, multiple regression, natural depression, neurotic depression, polyvinyl resin, psychotic depression, reactive depression, retarded depression, thermoplastic resin, thermosetting resin

7 syllables:
agitated depression, arithmetic progression, economics profession, exogenous depression, exponential expression, geometric progression, material possession

8 syllables:
chronological succession, ecological succession, idiomatic expression, war of the spanish succession

9 syllables:
war of the austrian succession