2 Syllables: SU
7, Aaron, Baron, barren, beckon, Bedlam, bellum, Bremen, brethren, Breton, cession, Clarence, Clemens, Clement, crescent, currant, deaden, deference, Devon, Edmond, Edmund, Edwin, Ellen, Epsom, errand, errant, Essen, essence, Evan, extant, felon, freshened, harem, heaven, Helen, heron, Hessian, Karen, leaden, leaven, Leben, legend, lemon, Lenin, lessen, lesson, melon, parent, peasant, Pelham, penance, pennant, pheasant, pleasant, Plenum, preference, pregnant, presence, present, pression, Preston, question, reckon, rectum, reddened, reference, requiem, resin, Reverend, second, section, segment, septum, session, seven, sexton, Sharon, spectrum, Stephens, tenant, Terence, threaten, vellum, venom, veteran, weapon, weren, Weston
3 Syllables: SUU
3 Syllables: USU
aberrant, acceptance, accession, affection, aggression, apparent, assessment, collection, complexion, compression, conception, concession, confession, connection, connexion, contestants, convection, correction, deception, defection, deflection, dejection, depression, detection, digression, direction, discretion, ejection, election, erection, exception, expectant, expression, fluorescent, forbearance, impression, inception, incessant, infection, inflection, inherent, injection, inspection, intestine, investment, Lieutenant, Magellan, objection, obsession, oppression, perception, perfection, possession, predestined, procession, profession, progression, projection, protection, quiescence, quiescent, quintessence, reception, recession, reflection, reflexion, regression, rejection, repellent, repression, secession, selection, subjection, succession, suppression, transgression, transparent, unpleasant
4 Syllables: UUSU
acquiescence, adolescence, adolescent, cerebellum, circumspection, convalescence, convalescent, disaffection, effervescence, evanescent, imperfection, incandescent, indiscretion, insurrection, intercession, interregnum, intersection, introspection, iridescent, Mahometan, misconception, obsolescence, omnipresence, omnipresent, phosphorescent, preconceptions, predilection, prepossessions, recollection, reelection, resurrection, retrogression
Found 202 words across 4 groupings. Skipped 83 excess words of a similar stem.