Bird seen in wilderness (4)
I believe the answer is:
erne
'bird' is the definition.
(erne is a kind of bird)
'in wilderness' is the wordplay.
'in' indicates a hidden word.
'ERNE' is hidden within 'wilderness'.
'seen' is the link.
(Other definitions for erne that I've seen before include "Sea eagle and Northern loch" , "Large bird" , "Fish-eating sea eagle" , "Irish river, loughs; sea bird" , "White-tailed eagle" .)