Beach crawler (4)
I believe the answer is:
crab
'beach crawler' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for crab that I've seen before include "The constellation Cancer" , "Shellfish with pincers" , "Food from the sea" , "A crustacean; type of apple" , "Seashore crustacean" .)