Passes for females (4)
I believe the answer is:
does
This clue is a double definition.
'passes' is the first definition.
(doing is a kind of passing)
'females' is the second definition.
(female deer)
'for' acts as a link.
(Other definitions for does that I've seen before include "takes one for a ride" , "Acts" , "some females" , "about 50% of deer" , "Female deers" .)