2 Syllables: SU
3 Syllables: SUU
bearable, cerebral, clerical, credible, decimal, edible, enviable, equable, feasible, festival, genital, legible, medical, miracle, parable, peaceable, pedestal, plentiful, preferable, readable, reasonable, Reginald, regional, seasonal, seminal, sensible, several, skeletal, tenable, tentacles, terrible, ventricle
3 Syllables: UUS
4 Syllables: USUU
accessible, appreciable, chimerical, commendable, conceivable, confessional, congenital, Congressional, contemptible, defensible, dependable, detestable, ephemeral, execrable, illegible, impeccable, incredible, ineffable, insensible, lamentable, numerical, ostensible, polemical, presentable, procedural, professional, regrettable, satirical, unbearable, unenviable, unquenchable, unreasonable, unspeakable, untenable
4 Syllables: UUUS
5 Syllables: UUSUU
comprehensible, hypothetical, inaccessible, inconceivable, incontestable, indefensible, indigestible, indispensable, inexpressible, irremediable, irrepressible, irretrievable, reprehensible, unbelievable, unforgettable, unimpeachable
6 Syllables: UUUSUU
Found 88 words across 7 groupings. Skipped 7 excess words of a similar stem.