[day] n [ME, fr. OE daeg; akin to OHG tag day] (bef. 12c) 1 a: the time of light between one night and the next b: daylight 1, 2
2: the period of rotation of a planet (as earth) or a moon on its axis
3: the mean solar day of 24 hours beginning at mean midnight
4: a specified day or date
5: a specified time or period: age "in grandfather's ~"
6: the conflict or contention of the day "played hard and won the ~" 7: the time established by usage or law for work, school, or business 8: a period of existence or prominence of a person or thing -- day after day : for an indefinite or seemingly endless number of days -- day in, day out : for an indefinite number of successive days