Position I am in for getting fish (6)
I believe the answer is:
plaice
'fish' is the definition.
(I know that plaice is a type of fish)
I don't understand the rest of the clue.
Can you help me to learn more?
(Other definitions for plaice that I've seen before include "Position the fish, we hear" , "Large flat fish" , "Location of the fish" , "Tasty flatfish I place here" , "Flat fare" .)