repast vs potluck

repast and potluck both are nouns.

Word	Noun	Adjective	Verb	Adverb
repast	Yes	No	No	No
potluck	Yes	No	No	No

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

repast: the food served and eaten at one time
potluck: whatever happens to be available especially when offered to an unexpected guest or when brought by guests and shared by all

repast (noun)	potluck (noun)
the food served and eaten at one time	whatever happens to be available especially when offered to an unexpected guest or when brought by guests and shared by all