Fish's point of view (5)
I believe the answer is:
angle
I believe this clue is a triple definition!
'fish's' is the first definition.
(angling is a kind of fishing)
'point' is the second definition.
(I have seen 'Point of view' mean 'angle' so perhaps 'point' could also mean 'angle')
'of' acts as a link.
'view' is the third definition.
(angle is a kind of view)
(Other definitions for angle that I've seen before include "Right, acute or obtuse" , "Approach to problem" , "Point of view - fish" , "that is often right" , "Fish; viewpoint" .)