Here's what rhymes with castratable.
compatible incompatible Words that almost rhyme with castratable
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 hexagonal intangible octagonal supranational impalpable verapamil expandable international multinational transnational understandable interactional lnternational transactional ungrammatical semiannual nontaxable