True masculine domain (5)

I believe the answer is:

realm

'domain' is the definition.
(I know that realm is a type of domain)

'true masculine' is the wordplay.
'true' becomes 'real' (similar in meaning).
'masculine' becomes 'm'.
'real'+'m'='REALM'

(Other definitions for realm that I've seen before include "Kingdom could be lamer" , "Country" , "department" , "Area of influence" , "King's domain" .)

I've seen this clue in The Times and The Telegraph.

Want a hint initially instead of a full solution? Install my app