Stoker holding tail of coarse fish (5)
I believe the answer is:
bream
'fish' is the definition.
(I know that bream is a type of fish)
'stoker holding tail of coarse' is the wordplay.
'stoker' becomes 'bram' (I've seen this in another clue).
'holding' indicates putting letters inside.
'tail of' suggests the final letters.
The last letter of 'coarse' is 'e'.
'bram' going around 'e' is 'BREAM'.
(Other definitions for bream that I've seen before include "Swimmer" , "Fish of the carp family" , "Edible fish" , "Bar me from the freshwater fish" , "River fish" .)