Aerie builder (5)
I believe the answer is:
eagle
'aerie builder' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for eagle that I've seen before include "A glee-ful bird?" , "King of birds" , "Bird of prey, may be golden" , "Aglee (anag.)" , "two strokes fewer?" .)