send in phr v [T] 1 [ send sth ↔ in] to send something, usually by mail, to a place where it can be dealt with 提交〔某物至某地供处理，一般通过邮寄〕: Did you send in your application? 你把申请交了吗？ 2 [ send sb ↔ in] to send soldiers, police etc somewhere to deal with a dangerous situation 派遣〔士兵、警察等至某地处理危险情况〕: Finally, the mayor had to send in the police. 最后，市长不得不出动警力。