Adult female and first man (4)
I believe the answer is:
adam
'first man' is the definition.
(first man in the Bible)
'adult female' is the wordplay.
'adult' becomes 'a' (abbreviation).
'female' becomes 'dam' (dam is a kind of female).
'a'+'dam'='ADAM'
'and' is the link.
(Other definitions for adam that I've seen before include "Eden man" , "God's first son" , "the first orphan?" , "Biblical first human" , "first in the race?" .)