Greet wild bird (5)
I believe the answer is:
'bird' is the definition.
(egret is a kind of bird)
'greet wild' is the wordplay.
'wild' indicates anagramming the letters.
'greet' is an anagram of 'EGRET'.
(Other definitions for egret that I've seen before include "Wader with white plumage" , "flier" , "Heron-like wader" , "Kind of white heron - greet it" , "White wading-bird" .)