Damon of "The Martian” (4)
I believe the answer is:
matt
'damon of the martian' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for matt that I've seen before include "Dull, not shiny" , "Not glossy" , "Dull uniform finish" , "Non-gloss" , "(Of surface) dull" .)