Gull (4)
There are a few possibilities for this:
kittiwake
'gull' is the definition.
(synonyms)
This is all the clue.
(Other definitions for dupe that I've seen before include "Put one over on, cod" , "Puppet" , "Deceive, trick" , "One deceived, tricked" , "Cat's paw" .)
'gull' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for tern that I've seen before include "Small slender gull" , "Long-winged aquatic bird" , "Gull-like seabird" , "Gull-like sea bird" , "Fork-tailed relative of the gull" .)
'gull' is the definition.
(I have seen 'A gull ' mean 'skua' so perhaps 'gull' could also mean 'skua')
This is the entire clue.
(Other definitions for skua that I've seen before include "Gull-like rapacious bird" , "Predatory northern seabird" , "Large brown seabird" , "Large predatory bird" , "One preying on gulls" .)
'gull' is the definition.
(kittiwake is a kind of gull)
This is the entire clue.
(Other definitions for kittiwake that I've seen before include "Small pearl-grey gull" , "A seagull" , "Bird" , "Arctic gull with yellow bill and black legs" , "Oceanic gull" .)