Delightful diversion (4)
I believe the answer is:
romp
'delightful diversion' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for romp that I've seen before include "light-hearted outing" , "Energetic play" , "High jinks" , "Play in a lively way, like children" , "Play boisterously" .)