Or search: confuse, confound
3 Syllables: SUU
clarify, emphasise, emphasize, specify, terrify, verify
4 Syllables: USUU
exemplified, exemplifies, exemplify, identified, identifies, identify, indemnify
5 Syllables: UUSUU
unidentified

Found 14 words across 3 groupings. Skipped 2 excess words of a similar stem.