Reportedly unearthly bird's nest (5)
I believe the answer is:
eyrie
'bird's nest' is the definition.
(eyrie is a kind of bird's nest)
'reportedly unearthly' is the wordplay.
'reportedly' indicates a 'sounds like' (homophone) clue.
'unearthly' becomes 'eerie' (I've seen this in another clue).
'eerie' is a homophone of 'EYRIE'.
(Other definitions for eyrie that I've seen before include "home hard to reach" , "top spot" , "high point" , "Eagle nest" , "Lofty home" .)