occasion vs function

occasion and function both are nouns.

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

As nouns, occasion and function are synonyms defined as:

occasion and function: a formal or official social gathering or ceremony of people

Other synonyms of occasion include affair, social affair, social function, social gathering, social occasion.

As nouns, function is a hyponym of occasion; that is, function is a word with a more specific, narrower meaning than occasion:

occasion (noun)	function (noun)
an event that occurs at a critical time	the actions and activities assigned to or required or expected of a person or group
a formal or official social gathering or ceremony of people	what something is used for
a rational motive for a belief or action	a set sequence of steps, part of larger computer program
an opportunity to do something	a formal or official social gathering or ceremony of people
the time of a particular event	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

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