Heron's home (4)
I believe the answer is:
nest
'heron's home' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for nest that I've seen before include "Place of retreat" , "In which to lay eggs or give birth" , "Accommodation for hobby, say" , "Casually thrown" , "Cosy home like bird's" .)