D-day

or D-Day

[dee-dey]

noun

Military. the day, usually unspecified, set for the beginning of a planned attack.
June 6, 1944, the day of the invasion of western Europe by Allied forces in World War II.
Informal. any day of special significance, as one marking an important event or goal.

Origin of D-day

Dutch (for day) + day; the same pattern as H-hour

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

Related Words for d-day

climax, contingency, crisis, crossroad, crossroads, deadline, emergency, exigency, juncture, pinch, strait, target, countdown, D-day, H-hour, term

Examples from the Web for d-day

Contemporary Examples of d-day

Williams interviewed and profiled four D-Day veterans, showing his sensitive side without ever seeming maudlin.
Hillary Clinton’s Network Massage
Tom Shales
June 10, 2014
D-Day was the first successful opposed landing on French territory—the country was held by the Nazis—in over 800 years.
D-Day 70th Anniversary Celebrations: Queen, Obama, Merkel, Putin and Cameron in France
Tom Sykes
June 6, 2014
D-Day was 70 years ago, and to midshipmen of today, it is all but ancient history.
D-Day Historian Craig Symonds Talks About History’s Most Amazing Invasion
Marc Wortman
June 5, 2014
There is a tendency to conceive of the Allied landings on D-Day as a single event, but in fact it was just the first step.
D-Day Historian Craig Symonds Talks About History’s Most Amazing Invasion
Marc Wortman
June 5, 2014
Did Churchill and Roosevelt agree about the when, where, and how of D-Day and the invasion of France?
D-Day Historian Craig Symonds Talks About History’s Most Amazing Invasion
Marc Wortman
June 5, 2014

British Dictionary definitions for d-day

D-day

noun

the day, June 6, 1944, on which the Allied invasion of Europe began
the day on which any large-scale operation is planned to start

Word Origin for D-day

C20: from D (ay) -day; compare H-hour

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for d-day

D-day

1918, "date set for the beginning of a military operation," with D as an abbreviation of day, cf. H-hour, also from the same military order of Sept. 7, 1918:

The First Army will attack at H-Hour on D-Day with the object of forcing the evacuation of the St. Mihiel salient. [Field Order No. 8, First Army, A.E.F.]

"They designate the day and hour of the operation when the day and hour have not yet been determined, or where secrecy is essential" [U.S. Army Center of Military History Web site]. Now almost exclusively of June 6, 1944.

d-day in Culture

D-Day

The code name for the first day of a military attack, especially the American and British invasion of German-occupied France during World War II on June 6, 1944 (see invasion of Normandy). This marked the beginning of the victory of the Allies in Europe. Germany surrendered less than a year later.