Merits different title (6)
I believe the answer is:
mister
'title' is the definition.
'merits different' is the wordplay.
'different' indicates anagramming the letters.
'merits' with letters rearranged gives 'MISTER'.
(Other definitions for mister that I've seen before include "Set rim (anag.)" , "Bloke" , "Form of address to a man, used without his name" , "Mr" , "Male form of address" .)