见义勇为

词典解释

[see what is right and have the courage to do it;be ready to take up the cudgets for a just cause;do boldly what is righteous;be zealous in doing what is righteous in seeing it] 意识到是正义之举就大胆去做

成语解释

义：正义；勇：勇敢；为；做。见到正义的事情勇于去做。