1 the time between sunrise and sunset.
2 a a period of 24 hours as a unit of time, esp. from midnight to midnight, corresponding to a complete revolution of the earth on its axis. b a corresponding period on other planets (Martian day).
3 daylight (clear as day).
4 the time in a day during which work is normally done (an eight-hour day).
5 a (also pl.) a period of the past or present (the modern day; the old days). b (prec. by the) the present time (the issues of the day).
6 the lifetime of a person or thing, esp. regarded as useful or productive (have had my day; in my day things were different).
7 a point of time (will do it one day).
8 a the date of a specific festival. b a day associated with a particular event or purpose (graduation day; payday; Christmas day).
9 a particular date; a date agreed on.
10 a day's endeavour, or the period of an endeavour, esp. as bringing success (win the day).
Phrases and idioms:
all in a (or the) day's work part of normal routine. at the end of the day in the final reckoning, when all is said and done. call it a day end a period of activity, esp. resting content that enough has been done. day after day without respite. day and night all the time. day-boy (or -girl) Brit. a boy or girl who goes daily from home to school, esp. a school that also has boarders. day by day gradually. day care the supervision of young children during the working day. day centre a place providing care for the elderly or handicapped during the day. day-dream n. a pleasant fantasy or reverie.
—v.intr. indulge in this. day-dreamer a person who indulges in day-dreams. day in, day out routinely, constantly. day labourer an unskilled labourer hired by the day. day lily any plant of the genus Hemerocallis, whose flowers last only a day. day nursery a nursery where children are looked after during the working day. day off a day's holiday from work. Day of Judgement = Judgement Day. day of reckoning see RECKONING. day of rest the Sabbath. day out a trip or excursion for a day. day-owl any owl hunting by day esp. the short-eared owl. day release Brit. a system of allowing employees days off work for education. day return a fare or ticket at a reduced rate for a journey out and back in one day. day-room a room, esp. a communal room in an institution, used during the day. day-school a school for pupils living at home. day-to-day mundane, routine. day-trip a trip or excursion completed in one day. day-tripper a person who goes on a day-trip. not one's day a day of successive misfortunes for a person. on one's day at one's peak of capability. one of these days before very long. one of those days a day when things go badly. some day at some point in the future. that will be the day colloq. that will never happen. this day and age the present time or period.
Etymology: OE daeligg f. Gmc
Useful english dictionary. 2012.