basis vs fundament

basis and fundament both are nouns.

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

As nouns, basis and fundament are synonyms defined as:

basis and fundament: the fundamental assumptions from which something is begun or developed or calculated or explained

Other synonyms of basis include base, cornerstone, foundation, groundwork.

basis (noun)	fundament (noun)
the fundamental assumptions from which something is begun or developed or calculated or explained	lowest support of a structure
a relation that provides the foundation for something	the fleshy part of the human body that you sit on
the most important or necessary part of something	the fundamental assumptions from which something is begun or developed or calculated or explained