D-day

or D-Day

[ dee-dey ]

noun

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

D-day

noun

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

D-Day

1. 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.

Word History and Origins

Origin of D-day¹

First recorded in 1918; D (for day ) + day; the same pattern as H-hour

Word History and Origins

Origin of D-day¹

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

Example Sentences

Amy renamed the days of the week A-day, B-day, C-day, D-day, E-day, F-day and G-day.

From FiveThirtyEight

It must have been one of the big highs of the war, to be in London and hit the pubs during the last two months before D-Day.

From The Daily Beast

For the citizens of that city, this event has a deeper, more sentimental meaning than even D-Day.

From The Daily Beast

Williams interviewed and profiled four D-Day veterans, showing his sensitive side without ever seeming maudlin.

From The Daily Beast

D-Day was the first successful opposed landing on French territory—the country was held by the Nazis—in over 800 years.

From The Daily Beast

D-Day was 70 years ago, and to midshipmen of today, it is all but ancient history.

From The Daily Beast

The end of a perfect d-day she tried to grin, her teeth chattering with cold.

From Project Gutenberg