Surprisingly greet a bird (5)
I believe the answer is:
egret
'a bird' is the definition.
(egret is a kind of bird)
'surprisingly greet' is the wordplay.
'surprisingly' indicates an anagram (a surprising ordering of the letters).
'greet' is an anagram of 'EGRET'.
(Other definitions for egret that I've seen before include "young bird" , "Mainly white heron" , "Bird eating fish" , "Wading bird like a heron" , "white fish eater" .)