2 syllables:
cession, deshane, deshon, eschen, flesh in, freshen, fresh in, heshen, hessian, hession, leshan, pression, pressione, question, session, sheshan, teschen

3 syllables:
abscession, accession, addression, aggression, agression, assession, bull session, closed session, compression, concession, confession, congression, decession, degression, depression, digression, discession, discretion, egression, espressione, excession, expression, helvetian, impression, incession, ingression, insession, jam session, mancession, midsession, monecian, noetian, obsession, oppression, perpession, possession, precession, procession, profession, progression, rap session, recession, refreshen, regression, repression, s-expression, seccession, secession, sezession, skull session, succession, sucession, suppression, supression, transgression, vanessian

4 syllables:
de-accession, decompression, derepression, dispossession, great depression, health profession, indiscretion, intercession, intersession, introcession, introgression, intropression, learned profession, misexpression, misimpression, multisession, non-aggression, non-possession, nonaggression, practice session, prepossession, radieschen, recompression, reimpression, repossession, retrocession, retrogression, self-expression, self-possession, sense impression, special session, subingression, supersession, uncompression, wage concession

5 syllables:
circumincession, facial expression, image compression, kathavasheshan, legal profession, line of succession, manic-depression, manic depression, meta-regression, microaggression, microexpression, overexpression, peripatecian, photo-secession, secret obsession, simple regression, taking possession, transferred possession, without expression

6 syllables:
clinical depression, executive session, harmonic progression, immunosuppression, indirect expression, linear regression, medical profession, multiple regression, myelosuppression, natural depression, neurotic depression, psychotic depression, reactive depression, retarded depression

7 syllables:
agitated depression, arithmetic progression, covid-19 recession, 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

2 syllables:
caisson, cresson, deafen, devon, essen, evan, heaven, leaven, lessen, lesson, resin, seven, stetson

3 syllables:
eleven, c-section, dance lesson, french lesson, golf lesson, gum resin, phaethon

4 syllables:
german lesson, hebrew lesson, language lesson, music lesson, object lesson, seventh heaven, tennis lesson, tree of heaven, twenty-seven, vault of heaven, vinyl resin

5 syllables:
acrylic resin, amino resin, cannabis resin, delicatessen, epoxy resin, history lesson, manna from heaven, melamine resin, natural resin, phenolic resin, piano lesson, silicone resin, synthetic resin, violin lesson

6 syllables:
polyvinyl resin, thermoplastic resin, thermosetting resin