Heron bagged by hunter, gentleman from the south (5)
I believe the answer is:
egret
'heron' is the definition.
(egret is a kind of heron)
'bagged by hunter gentleman from the south' is the wordplay.
'bagged by' indicates a hidden word (the solution is bagged up or contained by the clue).
'from the south' says the letters should be written backwards (in a down clue, letters go up).
'terge' can be found hidden inside 'hunter gentleman'.
'terge' in reverse letter order is 'EGRET'.
(Other definitions for egret that I've seen before include "Wader with white plumage" , "White wading-bird" , "White-plumed wader" , "Bird eating fish" , "Type of forty eight Ac" .)