Or search: finish, finishing, completion, graduation, culmination, termination, consummation, finalisation, finalization
2 Syllables: SU
cited, climate, diet, guided, Isaac, kindest, lighted, minded, Pilate, pilot, private, quiet, riot, sided, sighted, tiniest, violets, Wyatt
3 Syllables: USU
delighted, disquiet, excited, invited, presided, provided, recited, reminded, United
4 Syllables: UUSU
coincided, elegiac

Found 29 words across 3 groupings. Skipped 4 excess words of a similar stem.