Masculine or feminine (6)
I believe the answer is:
gender
I believe this clue is a double definition.
'masculine' is the first definition.
(thesaurus)
'feminine' is the second definition.
(thesaurus)
(Other definitions for gender that I've seen before include "What divides males and females" , "Sex category" , "Male or female state" , "Masculine, feminine or neuter" , "Man or woman" .)