n.
1) a chilly, cool; clear, nice; cloudy; cold; foggy; gloomy; hot, stifling; rainy; sunny; warm day
2) an eventful, field, memorable, red-letter day (we had a field day criticizing their report)
3) a holy; opening; visiting; wedding; working day (opening day of the baseball season)
4) day breaks, dawns (poetic)
5) by day (London by day)
6) by the day (to be paid by the day)
7) for a day (we are going to town for the day)
8) in a day (we cannot do the whole job in a day; back in the old days)
9) on a certain day (on the following day; on New Year's Day)
10) within several days (within ten days)
11) (misc.) day after day; day and night ('all the time'); D-day ('a day on which a significant event is scheduled to begin'); to take a day off; I rue the day ('I wish that that day had never been'); from day to day; day in, day out; to carry the day ('to be victorious'); the other day ('recently'); his days are numbered ('he will die soon'); the dog days ('the hot days of July and August'); halcyon days; the good old days; it was a big ('successful') day for our team; to take one day at a time; judgment day; on the day (BE; colloq.) ('when the time comes')
USAGE NOTE: The collocation by day contrasts with by night (London by day is very different from London by night),
(see the Usage Note for night)