injustice
noun /ɪnˈdʒʌstɪs/
  /ɪnˈdʒʌstɪs/
[uncountable, countable]Idioms - the fact of a situation being unfair and of people not being treated equally; an unfair act or an example of unfair treatment
- We are committed to fighting against poverty and injustice.
 - a burning sense of injustice
 - Social and political injustice seemed to be getting worse rather than better.
 - She was enraged at the injustice of the remark.
 - The report exposes the injustices of the system.
 
Extra Examples- It would be an injustice to the man to imprison him for life.
 - She remains adamant that an injustice was done.
 - She was acclaimed for speaking out against injustice.
 - She was overwhelmed by the injustice of it all.
 - The trial was regarded as the greatest injustice of the post-war criminal justice system.
 - They see the injustice and want to help.
 - a novel that sets out to expose social injustice
 - a terrible injustice by the police
 - people who work hard to correct society's injustices
 - I did not really see myself as a victim of injustice.
 - She felt a burning sense of injustice with regard to the situation.
 - The court decided that he certainly had suffered an injustice.
 - They were convinced that a grave injustice had been done.
 
Oxford Collocations Dictionaryadjective- grave
 - great
 - gross
 - …
 
- experience
 - suffer
 - regard something as
 - …
 
- injustice by
 - injustice to
 
- the injustice of it all
 - a sense of injustice
 - a victim of injustice
 - …
 
Word Originlate Middle English: from Old French, from Latin injustitia, from in- ‘not’ + justus ‘just, right’. 
Idioms 
do yourself/somebody an injustice 
- to judge yourself/somebody unfairly
- We may have been doing him an injustice. This work is good.
 - Perhaps I'm doing you an injustice.