matter vs affair

matter and affair both are nouns.

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

As nouns, matter and affair are synonyms defined as:

Other synonyms of matter include thing.

matter (noun)	affair (noun)
that which has mass and occupies space	a vaguely specified concern
(used with negation) having consequence	a formal or official social gathering or ceremony of people
some situation or event that is thought about	a usually secretive or illicit sexual relationship
a vaguely specified concern
a problem
written works (especially in books or magazines)

matter (verb)	affair (verb)
have weight; have import, carry weight