2 Syllables: SU
Barrett, belted, Bennet, Bennett, Celtic, checklist, chemist, cherished, cleric, credit, debit, desperate, epic, Eric, Erich, Essex, ethic, fairest, ferric, Frederic, Frederick, garret, Garrett, Garrick, Herrick, melted, menaced, merits, metric, pelted, pelvic, perished, prelate, relic, relished, respite, Senate, welded
3 Syllables: SUU
3 Syllables: USU
acetic, aesthetic, angelic, appellate, ascetic, athletic, authentic, barbaric, cosmetic, decrepit, domestic, embellished, emetic, endemic, esthetic, generic, genetic, geometric, Hellenic, Homeric, hysterics, kinetic, magnetic, majestic, obstetrics, pathetic, phonetic, poetic, polemic, prophetic, replenished, symmetric, synthetic, systemic, theoretic, unblemished
4 Syllables: UUSU
academic, apathetic, arithmetic, atmospheric, diabetic, energetic, epidemic, esoteric, hygienic, pathogenic, sympathetic
5 Syllables: UUUSU
6 Syllables: UUUUSU
Found 90 words across 6 groupings. Skipped 17 excess words of a similar stem.