Caught one departing in chopper (7)
I believe the answer is:
cleaver
'chopper' is the definition.
('cleaver' can be a synonym of 'chopper')
'caught one departing' is the wordplay.
'caught' becomes 'c' (cricket abbreviation).
'one departing' becomes 'leaver' (I've seen this before).
'c'+'leaver'='CLEAVER'
'in' is the link.
(Other definitions for cleaver that I've seen before include "Butcher's chopper" , "dangerous object?" , "A clever sort of axe" , "Meat axe" , "A butcher's chopping tool" .)