Cool headed flier involved in crime (5)
I believe the answer is:
crook
'involved in crime' is the definition.
Although both the answer and definition are singular nouns, I can't see how they can define each other.
'cool headed flier' is the wordplay.
I cannot really understand how this works, but
'flier' could be 'rook' (rook is a kind of birdanimal) and 'rook' is located in the answer.
A single letter 'c' remains which might be clued in a way I don't see.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for crook that I've seen before include "Something kinky" , "Shepherd's staff" , "Hooked staff" , "Bend; criminal; staff" , "Swindler - crosier - ill (in Australia)" .)