Close predator (4)
I believe the answer is:
seal
This could be a double definition.
'close' is the first definition.
(sealing is a kind of closing)
'predator' is the second definition.
The answer and definition can be both animals as well as being singular nouns.
Maybe you can see a link between them that I don't see?
Can you help me to learn more?
(Other definitions for seal that I've seen before include "Marine animal or sign of authenticity" , "Fasten with hot wax" , "Authenticating stamp" , "Ratify" , "Stick down" .)