Here's what rhymes with uncompleteable.
treatable repeatable unbeatable uneatable interpretable unrepeatable Words that almost rhyme with uncompleteable
readable reachable unreadable teachable teetotal unteachable unimpeachable impeachable feasible appreciable peaceable unbelievable believable inappreciable cleanable freezable regional agreeable seasonal unreasonable conceivable receivable unspeakable achievable redeemable perceivable unfeasible useable retrievable concealable resealable inconceivable foreseeable irretrievable indefeasible irredeemable unforeseeable paracetamol teacupful squeezable unuseable disagreeable interregional nonseasonal nonredeemable