by the back door
以非正规或不公开的方式进入或达到某个目标
口语·表示通过不正当或隐秘方式
英文释义
in a way that is indirect, secret, or not officially approved
例句
He got the job by the back door through his uncle's connections.
典故来源
源自房屋后门常为隐蔽入口，比喻非正式或秘密的途径。