Prom crowd (5)
I believe the answer is:
teens
'prom crowd' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for teens that I've seen before include "Years 13-19" , "The years 13 to 19" , "Adolescent years" , "Between 12 and 20" , "13-19 age group" .)