Merit second eccentric title (6)
I believe the answer is:
mister
'title' is the definition.
(I know that Mister is a type of title)
'merit second eccentric' is the wordplay.
'second' becomes 's' (common abbreviation).
'eccentric' indicates anagramming the letters.
'merit'+'s'='merits'
'merits' anagrammed gives 'MISTER'.
(Other definitions for mister that I've seen before include "that's what you'd call him" , "Mr" , "Form of address to a man, used without his name" , "Set rim (anag.)" , "Bloke" .)