Male title (3)
I believe the answer is:
sir
'male title' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for sir that I've seen before include "Formal and deferential address to a man" , "Way to address gentleman" , "Noble title of undesirable kind" , "Formal term of address" , "Form of address for a knight" .)