Prom or ball
I believe the answer is:
dance
This clue is a double definition.
'prom' is the first definition.
(thesaurus)
'ball' is the second definition.
(ball can mean an event for dancing)
(Other definitions for dance that I've seen before include "Jig, say" , "Eg, perform ballet" , "Fling" , "Eg, tango, waltz" , "Flamenco, perhaps" .)