fundraiser vs affair

fundraiser and affair both are nouns.

Word	Noun	Adjective	Verb	Adverb
fundraiser	Yes	No	No	No
affair	Yes	No	No	No

As nouns, affair is a hypernym of fundraiser; that is, affair is a word with a broader meaning than fundraiser:

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

fundraiser (noun)	affair (noun)
a social function that is held for the purpose of raising money	a vaguely specified concern
someone who solicits financial contributions	a formal or official social gathering or ceremony of people
	a usually secretive or illicit sexual relationship