activity vs bodily function

activity and bodily function both are nouns.

Word	Noun	Adjective	Verb	Adverb
activity	Yes	No	No	No
bodily function	Yes	No	No	No

As nouns, activity and bodily function are synonyms defined as:

activity and bodily function: an organic process that takes place in the body

Other synonyms of activity include bodily process, body process.

activity (noun)	bodily function (noun)
any specific behavior	an organic process that takes place in the body
the trait of being active; moving or acting rapidly and energetically
an organic process that takes place in the body
a process existing in or produced by nature (rather than by the intent of human beings)
the state of being active
(chemistry) the capacity of a substance to take part in a chemical reaction