Show second-rate players taking on course (9)
I believe the answer is:
broadcast
'show' is the definition.
(I know that broadcast is a type of show)
'second-rate players taking on course' is the wordplay.
'second rate' becomes 'b'.
'players' becomes 'cast' (group of actors).
'taking on' means one lot of letters go next to another.
'course' becomes 'road' (I've seen this before).
'cast' after 'road' is 'roadcast'.
'b'+'roadcast'='BROADCAST'
(Other definitions for broadcast that I've seen before include "Send out by radio or television" , "Transmit by radio/TV" , "Transmit over airwaves" , "Send out over the airwaves" , "Transmit by radio or television" .)