Western fish is extra (4)
I believe the answer is:
wide
'is extra' is the definition.
(cricket term)
'western fish' is the wordplay.
'western' becomes 'w'.
'fish' becomes 'ide' (I've seen this before).
'w'+'ide'='WIDE'
(Other definitions for wide that I've seen before include "Far from the target" , "Extending far" , "Expansive" , "roomy" , "Of vast scope" .)