supper vs affair

supper and affair both are nouns.

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

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

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