Or search: flip, sass, greet, react, repay, stool, bridle, marvel, reject, rejoin, retort, bristle, explode, respond, riposte
2 Syllables: SU
Ahmed, bonded, bonnet, chronic, comet, comic, conduct, conduit, conflict, conic, construct, convict, daunted, gauntlet, haunted, prompted, sonic, sonnet, taunted, tonic, vaunted, vomit, wanted
3 Syllables: USU
atomic, carbonic, harmonic, Ionic, ironic, Islamic, laconic, Mahomet, Masonic, misconduct, Platonic, sardonic, Teutonic, unconquered, undaunted, unwanted
4 Syllables: UUSU
corresponded, economic, electronic, embryonic, histrionic
5 Syllables: UUUSU
Napoleonic
7 Syllables: UUUUUSU
socioeconomic

Found 46 words across 5 groupings. Skipped 9 excess words of a similar stem.