0 a letter that cannot be delivered to the address written on it and cannot be returned to the person who sent it:
the dead-letter office
For a variety of reasons such orders and decrees often remained a dead letter.
In their legal discussions, the rabbis piled up legal technicalities, reducing the irksome biblical command to a dead letter.
Clearing the dead letter file, however, required assigning programmers from separate divisions who had never worked as a team before.
This bill may benefit organized labor, or it may be like many other laws now on the statute books - a dead letter.
In other cases, those that had become a dead letter remained because it was not acceptable to change the laws of the ancestors.
For a decade, however, this constitution was a dead letter.
In many cases, "bad" practices persisted despite the official public announcements, which became no more than a dead letter.
Reforms have ground to a halt and those implemented are basically dead letter.
