: a letter that cannot be delivered or returned by the post office because of an incorrect address or other problem
: a law or agreement that has lost its force or authority
What made you want to look up dead letter? Please tell us where you read or heard it (including the quote, if possible).
Take Our 10-Question Quiz
The commonly misspelled words quiz
How strong is your vocabulary?
The Vocab Quiz Game for iPhone & iPad
"Incredibly fun and addictive. And informative!" User Review, iTunes