Or search: unalike, likeness, similarity
2 Syllables: SU
fiddler, listener, prisoner, simpler
3 Syllables: SUU
Christopher, insular, minister, similar, singular, titular, vinegar, Whitaker
4 Syllables: USUU
Commissioner, conspirator, deliverer, inquisitor, parishioners, Peninsular, perimeter, petitioner, practitioner, solicitor

Found 22 words across 3 groupings. Skipped 11 excess words of a similar stem.