Is sick after right complaint (7)
I believe the answer is:
railing
'is sick after right complaint' is the definition.
I can't tell whether this definition defines the answer.
'sick after right complaint' is the wordplay.
'sick' becomes 'ailing' (similar in meaning).
'after' is a charade indicator (letters next to each other).
'right complaint' becomes 'r' (I can't explain this - if you can you should give a lot more credence to this answer).
'ailing' after 'r' is 'RAILING'.
Can you help me to learn more?
(Other definitions for railing that I've seen before include "Fencing - complaining - attacking" , "barrier appears" , "Type of fence - scoffing" , "Mocking" , "Barred metal fence" .)