Ready for some fun (4)
I believe the answer is:
game
This clue is a double definition.
'ready' is the first definition.
(thesaurus)
'some fun' is the second definition.
(thesaurus)
'for' acts as a link.
(Other definitions for game that I've seen before include "Eager; pastime" , "Eager and willing to accept challenge" , "Up for it; gamble" , "Competitive diversion" , "Willing to try" .)