Viewer's complaint is about critic after taking sides (6)
I believe the answer is:
iritis
'viewer's complaint' is the definition.
(I've seen this before)
'is about critic after taking sides' is the wordplay.
I cannot quite see how this works, but
'is' is present in the answer.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for iritis that I've seen before include "Eye inflammation" , "viewer's complaint" , "complaint of the eye" , "Complaint viewer has" .)