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