Female with a pass key (3)
I believe the answer is:
doe
'female' is the definition.
(female deer)
'pass key?' is the wordplay.
'pass' becomes 'do' (doing is a kind of passing).
'key?' becomes 'e' (a musical key).
'do'+'e'='DOE'
'with a' acts as a link.
(Other definitions for doe that I've seen before include "Buck's mate" , "Feminine counterpart of stag" , "possible mate for Rudolph?" , "A female deet" , "Female hare" .)