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