1977 movie thriller with Bo Derek (4)
I believe the answer is:
orca
'1977 movie thriller with bo derek' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for orca that I've seen before include "Massive killer" , "Large mammal" , "Killer at sea" , "Predatory black and white toothed whale" , "Cor! a killer whale" .)