What a thief may do is a hit (5)
I believe the answer is:
swipe
'a hit' is the definition.
(I know that swipe is a more specific form of hit)
I can't explain the remainder of the clue.
Can you help me to learn more?
(Other definitions for swipe that I've seen before include "Put (card) through reader; take without asking" , "Blow - nick" , "Hit with swinging blow, or slangily steal" , "Put (card) through reader; hit" , "Steal; pass a card through a reader" .)