2 Syllables: SU
Bunsen, Bunyan, Drummond, drunken, Duncan, dungeon, function, humdrum, huntsman, junction, London, London's, luncheon, onion, pumpkins, pungent, shrunken, someone, someone's, summon, sunken, tungsten, unction
3 Syllables: USU
abundance, abundant, assumption, circumference, Columbian, compunction, conjunction, consumption, encumbrance, incumbent, incumbrance, injunction, presumption, recumbent, redundant, resumption, triumphant
5 Syllables: UUUSU
Found 42 words across 3 groupings. Skipped 12 excess words of a similar stem.