Throw out of Doncaster (4)
I believe the answer is:
cast
'throw out' is the definition.
(I've seen this before)
'of doncaster' is the wordplay.
'of' indicates a hidden word.
'CAST' is hidden within 'doncaster'.
(Other definitions for cast that I've seen before include "Throw a fishing line" , "Select actors for play or film" , "Allot roles in a play" , "Set of performers" , "Discard; mould" .)