Dispatched from Isleworth (4)
I believe the answer is:
slew
'dispatched' is the definition.
(I've seen this before)
'from isleworth' is the wordplay.
'from' says the answer is hidden in the clue.
'SLEW' is hidden in the letters of 'isleworth'.
(Other definitions for slew that I've seen before include "Move obliquely or sideways, often losing control" , "Suddenly turn" , "Killed in archaic way" , "Quite a number" , "Dispatched" .)