Here's what rhymes with interpolational.
educational operational relational observational rotational locational avocational aberrational occupational vocational motivational vibrational generational gestational navigational translational correlational ideational subnational variational mutational probational recreational conversational informational sensational situational conformational foundational inspirational intergenerational associational coeducational invitational computational gravitational denominational congregational transformational noneducational nonoperational nonvocational organizational organisational confrontational improvisational interdenominational nonoccupational representational nondenominational nonrepresentational Words that almost rhyme with interpolational
occasional available capable payable attainable debatable saleable salable breakable trainable assailable bailable claimable gradable obtainable insatiable traceable unavailable changeable unattainable ascertainable unassailable unshakable repayable unbreakable unshakeable degradable unsaleable erasable unsalable persuadable resalable incapable sustainable unchangeable biodegradable explainable unobtainable inflatable untraceable irreclaimable reclaimable conveyable nonbreakable interchangeable irreplaceable unsustainable maintainable replaceable mistakable embraceable unmistakable inescapable exchangeable microwavable noninterchangeable nonexchangeable