suppositious vs suppositional

suppositious and suppositional both are adjectives.

Word	Noun	Adjective	Verb	Adverb
suppositious	No	Yes	No	No
suppositional	No	Yes	No	No

As adjectives, suppositious and suppositional are synonyms defined as:

suppositious and suppositional: based primarily on surmise rather than adequate evidence

Other synonyms of suppositious include conjectural, divinatory, hypothetic, hypothetical, supposed, supposititious.

suppositious (adjective)	suppositional (adjective)
based primarily on surmise rather than adequate evidence	based primarily on surmise rather than adequate evidence