¦ noun
1. a twenty-four-hour period as a unit of time, reckoned from one midnight to the next and corresponding to a rotation of the earth on its axis.
the time between sunrise and sunset.
Astronomy a single rotation of a planet in relation to its primary.
2. a particular period of the past: the laws were very strict in those days.
(the day) the present time.
(days) a particular period in a person's life: my student days.
(one's day) the successful or influential period of a person's life.
¦ adjective working or done during the day.
Phrases
all in a day's work part of someone's normal routine.
any day informal at any time.
?under any circumstances.
call it a day decide to stop doing something.
day and night all the time.
day by day gradually and steadily.
day in, day out continuously or repeatedly over a long period.
day of reckoning a testing time when the degree of one's success or failure will be revealed. [with allusion to Judgement Day.]
day to day
1. happening or proceeding on a daily basis.
2. involving everyday routine.
one day (or some day or one of these days) at some time in the future.
one of those days a day when things go badly.
that will be the day informal that is very unlikely.
these days at present.
Origin
OE d?g, of Gmc origin; related to Ger. Tag.