Rather dull chap (4)
I believe the answer is:
matt
I believe this is a double definition.
'rather dull' is the first definition.
(as opposed to glossy)
'chap' is the second definition.
(man's name)
(Other definitions for matt that I've seen before include "Without a shine, dull" , "Not glossy" , "Lacking a shine" , "Non-gloss" , "gospel!" .)