Char or blacken (5)
I believe the answer is:
singe
This clue is a double definition.
'char' is the first definition.
(I know that singe is a type of char)
'blacken' is the second definition.
(I know that singe is a type of blacken)
(Other definitions for singe that I've seen before include "Scorch lightly" , "Burn superficially" , "Effect of fire" , "Result of match accident" , "Superficial burn" .)