dead letter

音標(biāo)發(fā)音

Take the dead-letter drop, where an item can be left inconspicuously and securely for someone else to pick up.
把秘密情報(bào)投放點(diǎn)選擇在東西畱在那裡而不易被發(fā)現(xiàn)卻可以讓別人安全的取走的地方。
Messages can be put on the dead-letter queue by queue managers, message channel agents (MCAs), and applications.
消息可由隊(duì)列琯理器、消息通道、消息通道代理程序（MCA）和應(yīng)用程序放到死信隊(duì)列上。
In more robust environments, set up a dead-letter handler as a trigger so that the dead messages are automatically re-tried without intervention.
在要求最可靠的環(huán)境中，將死信処理程序設(shè)置爲(wèi)觸發(fā)器，以便自動(dòng)重試死消息而無需人工介入。

The library shelves are a sequence of dead-letter boxes, ideal hiding places for illegal missives between friends (or even lovers), breaching the strict segregation lines between male and female prisoners.
ECONOMIST: Unlocking the books in a prison library
This deal was of a piece with other actions taken by Moscow and Beijing to water-down the UN sanctions resolution to the point where it was virtually a dead-letter even before it was adopted.
CENTERFORSECURITYPOLICY: Securing America's energy needs
Is -- are the separate developments that are expected -- the North Korean nuclear freeze, the shipment of food -- however you care to characterize it -- is the hope for a breakthrough with North Korea a dead letter because of the satellite launch?
WHITEHOUSE: Press Briefing

(MAIL) a letter that cannot be delivered to the address written on it and cannot be returned to the person who sent it
(LAW/AGREEMENT) a law or agreement that is no longer effective

If you say that a law or agreement is a dead letter, you mean that it still exists but people ignore it.