打抱不平

打抱不平

Literally means:

defend someone against an injustice

Actually means:

right wrongs

It means fighting voluntarily against injustice or unfairness out of indignation in order to help the people who are bullied or unfairly treated. It usualy connotes a sense of praise or compliment.

出于对非正义行为或不公平事情的愤恨，主动跟这类行为或事情抗争，借以帮助受到不公平对待，或被欺负的一方。通常含有赞扬的意思。