Pardon bowler, maybe, after wide (4)
I believe the answer is:
what
'pardon' is the definition.
(I know that pardon can be written as what)
'bowler maybe after wide' is the wordplay.
'bowler maybe' becomes 'hat' (bowler is a type of hat).
'after' means one lot of letters go next to another.
'wide' becomes 'w' (abbreviation e.g. in cricket).
'hat' after 'w' is 'WHAT'.
(Other definitions for what that I've seen before include "Interrogatory word" , "Which thing?" , "That which - come again!" , "Eh?" , "I didn't hear" .)