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