Boat in "Jaws” (4)
I believe the answer is:
orca
'boat in jaws' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for orca that I've seen before include "Predatory black and white toothed whale" , "Marine creature" , "grampus" , "Killer at sea" , "Danger for swimmers" .)