Dollar for a deer (4)
I believe the answer is:
buck
I believe this clue is a double definition.
'dollar' is the first definition.
(slang)
'deer' is the second definition.
(male deer)
'for a' is the link.
(Other definitions for buck that I've seen before include "Dandy" , "American's ready" , "Male hare" , "Doe's mate" , "Male rabbit, deer etc" .)