- D-day is defined as a day when a military attack or important event is planned to take place.
An example of D-day was June 6, 1944 when France was invaded by the Allied forces in World War II.
Memorial to the soldiers who landed in Normandy on D-day, June 6th, 1944.
- The unnamed day on which an operation or offensive is to be launched.
- The day on which the Allied forces invaded France during World War II (June 6, 1944).
Origin of D-dayD (abbr. of day) + day.
Variant of D-day
Origin of D-dayD, the first letter of day