Partially burn; fish (4)
I believe the answer is:
char
I believe this clue is a double definition.
'partially burn' is the first definition.
(I've seen this in another clue)
'fish' is the second definition.
(char is a kind of fish)
(Other definitions for char that I've seen before include "Burn lightly" , "Drink" , "Tea - cleaning lady" , "One cleans" , "Fish < tea" .)