Fish heading away from seaweed (5)
I believe the answer is:
angle
'fish' is the definition.
(angle can mean to fish)
'heading away from seaweed' is the wordplay.
'heading away from' means to remove the first letter.
'seaweed' becomes 'tangle' (tangle is a type of seaweed).
'tangle' with its initial letter taken away is 'ANGLE'.
(Other definitions for angle that I've seen before include "crook" , "Opinion" , "Try to catch" , "Fish with hook and line" , "Point of view; old tribesman" .)