a Dear John letter

Dear John letter

A letter sent, typically from a woman to a man, to end a romantic relationship. Mike was clearly upset when he received a Dear John letter from his girlfriend, Caroline. He thought their relationship was going well and didn't expect it to end so suddenly. Mail call was usually a happy time in the military barracks, except for the unlucky soldiers who got Dear John letters from their sweethearts back home.
See also: dear, john, letter
Farlex Dictionary of Idioms.

a Dear John letter

a letter a woman writes to her boyfriend telling him that she does not love him anymore. Bert got a Dear John letter today from Sally. He was devastated.
See also: dear, john, letter
McGraw-Hill Dictionary of American Idioms and Phrasal Verbs.

Dear John letter

n. a letter a woman writes to her boyfriend in the military service telling him that she does not love him anymore. Sally sends a Dear John letter about once a month.
See also: dear, john, letter
McGraw-Hill's Dictionary of American Slang and Colloquial Expressions
See also:
  • Dear John letter
  • French letter
  • a bread-and-butter letter
  • bread-and-butter letter
  • a dead letter
  • dead letter
  • to whom it may concern
  • to whom this may concern
  • dash a letter off
  • Xmas