derriere vs fundament

derriere and fundament both are nouns.

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

As nouns, derriere and fundament are synonyms defined as:

derriere and fundament: the fleshy part of the human body that you sit on

derriere (noun)	fundament (noun)
the fleshy part of the human body that you sit on	lowest support of a structure
	the fleshy part of the human body that you sit on
	the fundamental assumptions from which something is begun or developed or calculated or explained