Anger in country reduced by good people (11)
I believe the answer is:
indignation
'anger' is the definition.
(I know that indignation is a type of anger)
'in country reduced by good people' is the wordplay.
'country reduced by good' becomes 'dig' (I can't explain this - if you can you should give a lot more credence to this answer).
'people' becomes 'nation'.
'in'+'dig'+'nation'='INDIGNATION'
Can you help me to learn more?
(Other definitions for indignation that I've seen before include "Outrage, dudgeon" , "righteous anger" , "Resentment" , "Annoyance at getting 12 down" .)