2 Syllables: SU
3 Syllables: SUU
bearable, cerebral, clerical, credible, decimal, edible, enviable, equable, festival, genital, legible, medical, parable, pedestal, plentiful, preferable, Reginald, seminal, sensible, several, skeletal, tentacles, terrible, ventricle
4 Syllables: USUU
accessible, amenable, chimerical, commendable, confessional, congenital, Congressional, contemptible, defensible, dependable, detestable, ephemeral, execrable, illegible, impeccable, incredible, ineffable, insensible, lamentable, numerical, ostensible, polemical, presentable, professional, regrettable, unbearable, unenviable, unquenchable, untenable
5 Syllables: UUSUU
comprehensible, hypothetical, inaccessible, incontestable, indefensible, indigestible, indispensable, inexpressible, irrepressible, reprehensible, unforgettable
6 Syllables: UUUSUU
Found 67 words across 5 groupings. Skipped 6 excess words of a similar stem.