Here's what rhymes with uncastratable.
compatible incompatible Words that almost rhyme with uncastratable
capital sagittal detachable unflappable nondetachable tractable laughable blamable practical rational fallible cannibal flammable passable chasuble cantabile satiable savable attractable national radical valuable casual tangible diagonal irrational palpable taxable adaptable implacable intractable mandible clavicle cantonal retractable bankable graspable frangible declarable fanciable grammatical maximal fractional impassable impractical infallible factional inflammable collapsible madrigal merchantable unpractical impassible nonflammable invaluable understandable hexagonal intangible octagonal supranational impalpable ungrammatical verapamil expandable international multinational transnational interactional lnternational transactional semiannual nontaxable