Military policeman given the bird (6)
I believe the answer is:
redcap
'military policeman' is the definition.
(redcap is a kind of military policeman)
I can't explain the remainder of the clue.
Can you help me to learn more?
(Other definitions for redcap that I've seen before include "bird!" , "Goldfinch" , "Carped (anag)" , "Military policeman (slang)" , "MP" .)