Sear fish (4)
I believe the answer is:
char
I believe this is a double definition.
'sear' is the first definition.
(I know that sear can be written as char)
'fish' is the second definition.
(char is a kind of fish)
(Other definitions for char that I've seen before include "new island > fish with > prepared wood, say" , "Brown" , "Scorch: trout-like fish" , "Partially burn; fish" , "Singe, scorch" .)