dd

Noun

day (plural days)

1. The time when the Sun is above the horizon and it lights the sky.
   • day and night; I work at night and sleep during the day.

   Synonyms:

   daylight, daylength, daytime, photoperiod

   Antonyms:

   night, nightertale, nighttide, nighttime, scotoperiod, skotoperiod

2. A period of time equal or almost equal to a full day-night cycle, being 24 hours long.
   • Holonyms: week < megasecond < fortnight < month < year < gigasecond < century < kiloannum, kiloyear, millennium < terasecond < mega-annum, megayear < petasecond < giga-annum, gigayear < exasecond < zettasecond < yottasecond < ronnasecond < quettasecond

   Synonyms:

   twenty-four hour day, 24-hour day, nychthemeron

   1. The time taken for the Sun to seem to be in the same place in the sky twice; a solar day.
   2. The time taken for the Earth to make a full rotation about its axis with respect to the fixed stars; a sidereal day or stellar day.
3. (informal) A 24-hour period beginning at 6am or sunrise.
   • Your 8am forecast: The high for the day will be 30 and the low, before dawn, will be 10.
4. A period of time between two set times which mark the beginning and the end of day in a calendar, such as from midnight to the following midnight or (Judaism) from nightfall to the following nightfall.
   • The day begins at midnight.

See all 24 meanings of day