(gay slang) A period of mild weather that permits men to wear garments light enough to reveal the contours of their genitalia.

(education) A day on which an institution (such as a farm or a university) hosts visitors who come to learn about it.

plural of access day

(aviation, military) An aviator (usually a fighter pilot) who destroys five or more enemy aircraft (the number required to become an ace) in a single day.

(informal) A day on which women hold a party around the time of Saint Valentine's Day, typically on February 13.

Short for Victory Day. / (informal) Short for Valentine's Day.

A day or time that has already passed.

plural of day gone by

A day in which bins, bags or boxes containing household or commercial waste or rubbish are collected, or due to be collected, by waste disposal officers (typically council employees called binmen or dustmen)

plural of bin day