1a period of time equal to a twenty-fourth part of a day and night and divided into 60 minutes:an extra hour of daylight in the winter eveningsrates of pay were low, starting at £3.20 an hour [as modifier, usually with preceding numeral]:a two-hour operation
a more indefinite period of time:during the early hours of the morning
the distance travelled in one hour:Ocean City is less than an hour away
2a time of day specified as an exact number of hours from midnight or midday:the clock in the sitting room struck the hour
(hours) [with preceding numeral] a time so specified on the twenty-four-hour clock:the first bomb fell at 0051 hours
the time as formerly reckoned from sunrise:it was about the ninth hour
3a fixed period of time for an activity, such as work, use of a building, etc.:the dinner hourlicensing hoursopening hours
a particular point in time:I wondered if my last hour had comeyou can’t turn him away at this hour
4 (hours) (in the Western (Latin) Church) a short service of psalms and prayers to be said at a particular time of day, especially in religious communities:an organized life of prayer including the canonical hours
5 Astronomy 15° of longitude or right ascension (one twenty-fourth part of a circle).
all hours
most of the time, especially outside the time considered usual:teenagers expect to be allowed to stay out to all hours
keep late (or regular) hours
get up and go to bed late (or at the same time) every day:she’d been under the impression that natives of Spanish-speaking countries kept late hours
on the hour
at an exact hour, or at the beginning of each hour, of the day or night:news bulletins all day on the hour
within the hour
after less than an hour:his response came within the hour
