Setter, participating in fun activities... (5)
I believe the answer is:
games
'setter participating in fun activities' is the definition.
'games' can be an answer for 'activities' (game is a kind of activity). I'm unsure of the 'setter participating in fun' bit.
'setter participating in fun activities' is the wordplay.
'setter' becomes 'me' (the setter of the clue).
'participating in' is an insertion indicator.
'fun activities' becomes 'gas' (gas is a kind of activity. I am not sure about the 'fun' bit.).
'me' put within 'gas' is 'GAMES'.
Can you help me to learn more?
(Other definitions for games that I've seen before include "See 12" , "Such as football, snap, etc" , "Sporting contests" , "Events collectively" , "School sports" .)