Hunters' cry, .... "Count ends with two!" (5-2)
I believe the answer is:
'hunters' cry' is the definition.
The definition suggests a singular noun which matches the answer.
'count ends with two' is the wordplay.
'count' becomes 'tally' (tallying is a kind of counting).
'ends' indicates one should take the final letters.
The last letters of 'with two' are 'ho'.
Can you help me to learn more?
(Other definitions for tally-ho that I've seen before include ""I've seen the fox!"", "Huntsperson's cry", "Fox-hunting cry", "Huntsman's cry", "Hunter's cry".)