dead-letter box死信箱
dead-letter E死信
dead-letter死信;逝世信;㰕
dead-letter queue死信队列;无效信件伫列
transactional dead-letter queue事务性死信队列
transaction dead-letter queue死信处理事务队列;事务处理死信队列
dead letter queue无用字母队列;死信队列
Dead Letter Perfect唱片名
dead letter detail名存实亡的风俗习惯
N-COUNT（可数名词） If you say that a law or agreement is a dead letter, you mean that it still exists but people ignore it. 空文
No one does anything about it and the law becomes a dead letter.
没人执行，该法律即成一纸空文。