Viewpoint no good: bitter about that? (5)
I believe the answer is:
angle
'viewpoint' is the definition.
(angle is a kind of viewpoint)
'no good bitter about that?' is the wordplay.
'no good' becomes 'ng' (abbreviation).
'bitter' becomes 'ale' (type of beer or bitter).
'about that?' indicates putting letters inside.
'ng' placed inside 'ale' is 'ANGLE'.
(Other definitions for angle that I've seen before include "Perspective" , "Fish with a rod" , "Corner - fish" , "may be right" , "Try to catch" .)