Bird continues to nest in hide (6)
I believe the answer is:
siskin
'bird' is the definition.
(siskin is a kind of bird)
'continues to nest in hide' is the wordplay.
'continues' becomes 'is' (I can't justify this - if you can you should believe this answer much more).
'to nest in' means one lot of letters goes inside another.
'hide' becomes 'skin' (a hide is an animal skin).
'is' placed within 'skin' is 'SISKIN'.
Can you help me to learn more?
(Other definitions for siskin that I've seen before include "Yellow-and-black finch" , "Small yellow and black finch" , "Little bird" , "Yellow-green bird" , "Yellowish-green finch" .)