Or search: puff, turk, pouf, stool, pouffe, tuffet, dynasty, hassock, osmanli
3 Syllables: SUU
documents, dominance, dominant, Donovan, fraudulent, Jonathan, prominence, prominent, Protestant, Providence, Robinson, Robinson's, Solomon, Solomon's, tolerance, tolerant
4 Syllables: USUU
concomitants, diocesan, improvidence, intolerance, intolerant, predominance, predominant, reconnaissance
4 Syllables: UUSU
concomitant
5 Syllables: UUSUU
cosmopolitan, metropolitan, Neapolitan

Found 28 words across 4 groupings. Skipped 1 excess word of a similar stem.