Be wary of a hunter, say (5)
I believe the answer is:
watch
'hunter say' is the definition.
(hunter is a kind of watch)
I cannot understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for watch that I've seen before include "See 21" , "Keep an eye on - timepiece" , "Timepiece - look out" , "period of duty" , "Keep under observation" .)