fundament vs supposition

fundament and supposition both are nouns.

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

As nouns, supposition is a hypernym of fundament; that is, supposition is a word with a broader meaning than fundament:

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

Other hypernyms of fundament include assumption, supposal.

fundament (noun)	supposition (noun)
lowest support of a structure	a hypothesis that is taken for granted
the fleshy part of the human body that you sit on	the cognitive process of supposing
the fundamental assumptions from which something is begun or developed or calculated or explained	a message expressing an opinion based on incomplete evidence