fundament vs sex activity

fundament and sex activity both are nouns.

Word	Noun	Adjective	Verb	Adverb
fundament	Yes	No	No	No
sex activity	Yes	No	No	No

fundament (noun)	sex activity (noun)
lowest support of a structure	activities associated with sexual intercourse
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