Or search: thinkable, conceivable
3 Syllables: SUU
fashionable, reasonable
4 Syllables: SUUU
applicable, charitable, habitable, navigable, palatable, pardonable, questionable, seasonable, treasonable
5 Syllables: USUUU
abominable, companionable, determinable, impressionable, inalienable, interminable, objectionable, unfashionable, unfathomable, unpalatable, unpardonable, unquestionable, unseasonable
6 Syllables: UUSUUU
ineradicable, unexceptionable, uninhabitable

Found 27 words across 4 groupings.