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

The naval island is where the Navy developed the Higgins boat — the pivotal landing craft that ferried troops to the beaches of Normandy during the D-day invasion.

From Los Angeles Times

First came France’s D-day beaches, then the heart of the once-divided German capital.

From Los Angeles Times

The beginning of the end of World War II occurred 80 years ago Thursday, when roughly 160,000 Allied troops made landfall in Normandy on D-day.

From Los Angeles Times

But it was a dark day for the families of 2,501 Americans who were killed and 5,000 wounded on D-day alone.

From Los Angeles Times

Alfie Booker still remembers the noises, smells and smoke from D-day.

From BBC