justification

n. /ˌdʒʌstɪfɪˈkeɪʃn/ C1

正当理由；辩护；根据

A good reason or explanation for something.

仙境例句

The Queen never needed any justification for shouting “Off with his head!”

王后喊“砍掉他的头！”从来不需要什么理由。