sex activity vs body process

sex activity and body process both are nouns.

Word	Noun	Adjective	Verb	Adverb
sex activity	Yes	No	No	No
body process	Yes	No	No	No

As nouns, body process is a hypernym of sex activity; that is, body process is a word with a broader meaning than sex activity:

Other hypernyms of sex activity include activity, bodily function, bodily process.

sex activity (noun)	body process (noun)
activities associated with sexual intercourse	an organic process that takes place in the body