Hasty escape (3)
I believe the answer is:
lam
'hasty escape' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for lam that I've seen before include "Batter" , "Hit hard, strike" , "On this, you're in flight, especially from the police" , "On this, you're fleeing, from the police" , "Go on the - - , (US sl.)" .)