affair vs social affair

affair and social affair both are nouns.

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

As nouns, affair and social affair are synonyms defined as:

affair and social affair: a formal or official social gathering or ceremony of people

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

affair (noun)	social affair (noun)
a vaguely specified concern	a formal or official social gathering or ceremony of people
a formal or official social gathering or ceremony of people
a usually secretive or illicit sexual relationship