affair vs supper

affair and supper both are nouns.

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

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

affair (noun)	supper (noun)
a vaguely specified concern	a light evening meal; served in early evening if dinner is at midday or served late in the evening at bedtime
a formal or official social gathering or ceremony of people	a social gathering where a light evening meal is served
a usually secretive or illicit sexual relationship