sleepover vs function

sleepover and function both are nouns.

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

As nouns, function is a hypernym of sleepover; that is, 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)
function: a formal or official social gathering or ceremony of people

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

sleepover (noun)	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)	the actions and activities assigned to or required or expected of a person or group
	what something is used for
	a set sequence of steps, part of larger computer program
	a formal or official social gathering or ceremony of people
	a formal or official social gathering or ceremony
	(mathematics) a mathematical relation such that each element of a given set (the domain of the function) is associated with an element of another set (the range of the function)
	a relation such that one thing is dependent on another

sleepover (verb)	function (verb)
	perform duties attached to a particular office or place or function
	perform as expected when applied
	serve a purpose, role, or function