sleeping vs bodily function

sleeping and bodily function both are nouns.

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

As nouns, bodily function is a hypernym of sleeping; that is, bodily function is a word with a broader meaning than sleeping:

Other hypernyms of sleeping include activity, bodily process, body process.

sleeping (noun)	bodily function (noun)
the suspension of consciousness and decrease in metabolic rate	an organic process that takes place in the body
quiet and inactive restfulness
the state of being asleep

sleeping (adjective)	bodily function (adjective)
lying with head on paws as if sleeping