basis vs supposal

basis and supposal both are nouns.

Word	Noun	Adjective	Verb	Adverb
basis	Yes	No	No	No
supposal	Yes	No	No	No

As nouns, supposal is a hypernym of basis; that is, supposal is a word with a broader meaning than basis:

basis: the fundamental assumptions from which something is begun or developed or calculated or explained
supposal: a hypothesis that is taken for granted

Other hypernyms of basis include assumption, supposition.

basis (noun)	supposal (noun)
the fundamental assumptions from which something is begun or developed or calculated or explained	a hypothesis that is taken for granted
a relation that provides the foundation for something	the cognitive process of supposing
the most important or necessary part of something