Aqua kin (4)
I believe the answer is:
teal
'aqua kin' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for teal that I've seen before include "Variety of small ducks" , "Duck - dark greenish-blue" , "Dark greenish-blue colour" , "Small, short-necked duck" , "bird" .)