Or search: hefty, stiff, tough, brawny, potent, robust, rugged, virile, grammar, forceful, muscular, vehement, bullocky, fortified, irregular
2 Syllables: SU
bronzes, calmness, commas, conduct, conduits, Congress, conscious, construct, dramas, fondest, fondness, gauntlet, genres, haunches, homage, honest, jaundice, launches, longest, Monmouth, monstrous, pompous, pontiff, promise, promptness, Thomas
3 Syllables: SUU
pianist
3 Syllables: USU
accomplice, Adonis, dishonest, misconduct, responses, subconscious, unconscious

Found 34 words across 3 groupings. Skipped 2 excess words of a similar stem.