sleepover vs social function

sleepover and social function both are nouns.

Word	Noun	Adjective	Verb	Adverb
sleepover	Yes	No	No	No
social function	Yes	No	No	No

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

sleepover: an occasion of spending a night away from home or having a guest spend the night in your home (especially as a party for children)
social function: a formal or official social gathering or ceremony of people

Other hypernyms of sleepover include affair, function, occasion, social affair, social gathering, social occasion.

sleepover (noun)	social function (noun)
an occasion of spending a night away from home or having a guest spend the night in your home (especially as a party for children)	a formal or official social gathering or ceremony of people