supper vs repast

supper and repast both are nouns.

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

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

supper: a light evening meal; served in early evening if dinner is at midday or served late in the evening at bedtime
repast: the food served and eaten at one time

Other hypernyms of supper include meal.

supper (noun)	repast (noun)
a light evening meal; served in early evening if dinner is at midday or served late in the evening at bedtime	the food served and eaten at one time
a social gathering where a light evening meal is served