Bitter about no-good viewpoint (5)
I believe the answer is:
angle
'viewpoint' is the definition.
(angle is a kind of viewpoint)
'bitter about no-good' is the wordplay.
'bitter' becomes 'ale' (type of beer or bitter).
'about' is an insertion indicator.
'no' becomes 'n' (common abbreviation).
'good' becomes 'g' (abbreviation).
'n'+'g'='ng'
'ale' going around 'ng' is 'ANGLE'.
(Other definitions for angle that I've seen before include "Fish; viewpoint" , "old invader" , "Fish with hook and line" , "Use a rod and line" , "that is often right" .)