Hunting cry (5-2)
I believe the answer is:
tally-ho
'hunting cry' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for tally-ho that I've seen before include "Huntsman's cry" , "Come on, hounds!" , "Hunter's cry" , "Cry of the huntsman pursuing the fox" , "Huntsperson's cry" .)