Who's prepared for entertainment? (4)
I believe the answer is:
show
'for entertainment?' is the definition.
(show is a kind of entertainment)
'who's prepared' is the wordplay.
'prepared' is an anagram indicator.
'whos' with letters rearranged gives 'SHOW'.
(Other definitions for show that I've seen before include "event" , "Point out - parade" , "Display cabinet" , "The world of entertainment" , "Labour's evidence for starting" .)