1 Syllable: S
Ian, leant
2 Syllables: SU
beacon, beaten, chieftain, Cleveland, credence, deacon, decent, deepen, demon, deviant, Eastman, Easton, eaten, Eaton, Eden, Eton, Freedman, freedmen, freedom, Freeman, Freeman's, frequent, Friedman, Grecian, Greenland, grievance, heathen, helium, legion, Leland, lenient, lesion, median, medium, Museum, Pekin, piquant, premium, prescience, reagent, reason, recent, refund, Regent, region, seaman, seamen, season, semen, sequence, Stephen, Steven, Sweden, sweeten, tedium, treason, treatment, weaken, Zealand
2 Syllables: US
3 Syllables: SUU
3 Syllables: USU
accretion, achievement, adhesion, agreement, allegiance, Archdeacon, Armenian, Athenian, bereavement, Bohemian, Cartesian, chameleon, cohesion, comedian, completion, concealment, convenience, convenient, depletion, Ephesians, excretion, expedient, impeachment, indecent, infrequent, ingredient, magnesium, Norwegian, obedience, obedient, Phoenician, policeman, secretion, uneven, unfrequent, Venetian
3 Syllables: UUS
4 Syllables: UUSU
antecedent, disagreement, disobedience, disobedient, epithelium, inconvenience, inconvenient, inexpedient, paroxysms
4 Syllables: UUUS
5 Syllables: UUUSU
Found 120 words across 9 groupings. Skipped 44 excess words of a similar stem.