supposal vs assumption

supposal and assumption both are nouns.

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

As nouns, supposal and assumption are synonyms defined as:

Other synonyms of supposal include supposition.

supposal (noun)	assumption (noun)
a hypothesis that is taken for granted	the act of taking possession of or power over something
the cognitive process of supposing	the act of assuming or taking for granted
	audacious (even arrogant) behavior that you have no right to
	a hypothesis that is taken for granted
	a statement that is assumed to be true and from which a conclusion can be drawn