hour / ou(ə)r/ • n. 1. a period of time equal to a twenty-fourth part of a day and night and divided into 60 minutes: an extra hour of daylight rates have ranged from $9 to $32 an hour | [as adj.] a two-hour operation. ∎  a less definite period of time: during the early hours of the morning. ∎  the distance traveled in one hour: Ocean City is less than an hour away.2. a point in time: I wondered if my last hour had come. ∎  a time of day or night: you can't turn him away at this hour. ∎  a time of day specified as an exact number of hours from midnight or midday: the clock in the sitting room struck the hour. ∎  (hours) a time so specified on the 24-hour clock: the first bomb fell at 0051 hours. ∎  the time as formerly reckoned from sunrise: it was about the ninth hour. ∎  the appropriate time for some specific action: now that the hour had come, David decided he could not face it.3. a period set aside for some purpose or marked by some activity: leisure hours. ∎  (hours) a fixed period of time for an activity, such as work, use of a building, etc.: shortened working hours.4. (usu. hours) (in the Western Church) a short service of psalms and prayers to be said at a particular time of day, esp. in religious communities.5. Astron. 15° of longitude or right ascension (one twenty-fourth part of a circle).PHRASES: all hours any time, esp. outside the time considered usual for something: intruders had access at all hours teenagers expect to be allowed to stay out to all hours.keep late hours get up and go to bed late.keep regular hours do the same thing at the same time every day.on the hour at an exact hour, or on each hour, of the day or night: news bulletins on the hour.within the hour after less than an hour.

hour one hour's sleep before midnight is worth two after traditional view of the most refreshing form of sleep; saying recorded from the mid 17th century.

See also the darkest hour is just before the dawn, at the eleventh hour, improve the shining hour, the witching hour.

hour XIII. ME. ure, our(e), later hour(e) — AN. ure, OF. ore, eure (mod. heure) :- L. hōra — Gr. hórā season, time of day, hour (cf. YEAR).