unprovoked
adj. 无缘无故的；未受挑衅的
例句
Her angry outburst was totally unprovoked.
她的暴跳如雷完全是无理取闹。
《牛津词典》
The half-truth is “unprovoked”.
“无缘无故”只能说是半真半假。
Epilepsy is defined by two or more unprovoked seizures.
癫痫是指两次或两次以上的无端发作。
