Here's what rhymes with undcfinable.
definable undefinable indefinable Words that almost rhyme with undcfinable
viable sizable sizeable desirable liable undesirable excitable assignable likable likeable decidable risible liveable advisable undeniable pliable notifiable survivable deniable climbable reliable justifiable unreliable inadvisable cognizable describable analyzable ascribable recyclable certifiable unlikeable nonassignable unliveable identifiable indescribable unjustifiable verifiable ammoniacal libidinal realizable classifiable indictable maniacal reconcilable unverifiable rectifiable recognizable irreconcilable unrecognizable demoniacal unidentifiable monomaniacal