potluck vs repast

potluck and repast both are nouns.

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

As nouns, repast is a hypernym of potluck; that is, repast is a word with a broader meaning than potluck:

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

Other hypernyms of potluck include meal.

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