He takes a gun out from a sliding compartment (6)
I believe the answer is:
drawer
'sliding compartment' is the definition.
(I've seen this before)
I don't understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for drawer that I've seen before include "Artist" , "Part of chest" , "Sliding box in chest" , "that's in a chest" , "Box in chest - one sketching?" .)