futile [ˈfju:taɪl]

以下由轻松背单词网站提供

adj.无效的，无用的，无希望的

(of actions ) having no effect or achieving nothing; unsuccessful

They were killed, to the last man, in a futile attack. 因为进攻失败，他们全部被杀，无一幸免。
Their efforts to revive him were futile. 他们对他抢救无效。