from The American Heritage® Dictionary of the English Language, 5th Edition.

  • noun The unnamed day on which an operation or offensive is to be launched.
  • noun The day on which the Allied forces invaded France during World War II (June 6, 1944).

from the GNU version of the Collaborative International Dictionary of English.

  • noun (Mil.) the day designated for the beginning of a planned attack by a military force; in communications the day is often otherwise unspecified for security reasons.
  • noun 6 June 1944, the day of the landing in France, by troops allied against the Germans in World War II.
  • noun informal the day for commencement or execution of any elaborate planned activity; -- often used jocosely.


from The American Heritage® Dictionary of the English Language, 4th Edition

[D (abbr. of day) + day.]


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  • In Washington, the countdown continues to what Americans are calling D-day, 2 August, when the US government says it would no longer be able to pay its bills within the existing debt ceiling of $14.3 trillion.

    The Guardian World News Timothy Garton Ash 2011

  • But Barclays Capital doesn't believe Aug. 2 really is D-day.

    Overheard 2011

  • Including Soviet forces in the invasion of Japan following their declaration of war on August 8, with D-day less than three months off, would have required rewriting the OPLAN.

    The Volokh Conspiracy » Not a May Day Parade 2010

  • Now forgive me if I am wrong but have we not just commemorated D-day and the brave men who laid down their lives to fight against the tyranny of fascism and wipe it from the face of Europe? only to send two fascists a few days later to Europe to represent us.

    Labour Suffers Historic Election Loss Dungeekin 2009

  • We had the chance to talk to one man who served in that war and World War Two, where he was almost killed on D-day.

    Heroes or Villains? 2010

  • This is all pre D-day, although the build up was taking place.

    Cheeseburger Gothic » A Sweet Jane alt-hist challenge! 2010

  • The NL however is anything but, and tomorrow brings a D-day for the Cardinals, Phillies, Brewers and D'Backs.

    Detroit Tigers v New York Yankees - live! | David Lengel 2011

  • He also writes about visiting the Hiroshima memorial in Japan in the final essay, which provided a strange juxtaposition to the D-day memorial here.

    Pictures of Paris darkerblogistan 2009

  • When D-day rolled around, Sigmon felt fantastic, and the practice jump off a three-story parking garage was easy.

    Cashathon: The Rise of Charity Races Anne Kadet 2011

  • A bomb was dropped on us but it just missed on D-day.

    Heroes or Villains? 2010


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