supposition vs surmisal

supposition and surmisal both are nouns.

Word	Noun	Adjective	Verb	Adverb
supposition	Yes	No	No	No
surmisal	Yes	No	No	No

As nouns, supposition and surmisal are synonyms defined as:

supposition and surmisal: a message expressing an opinion based on incomplete evidence

Other synonyms of supposition include conjecture, guess, hypothesis, speculation, surmise.

supposition (noun)	surmisal (noun)
a hypothesis that is taken for granted	a message expressing an opinion based on incomplete evidence
the cognitive process of supposing
a message expressing an opinion based on incomplete evidence