hour

American  

[ou^uhr, ou-er] / aʊər, ˈaʊ ər /

noun

1. a period of time equal to one twenty-fourth of a mean solar or civil day and equivalent to 60 minutes.

   He slept for an hour.

2. any specific one of 24 periods of 60 minutes, usually reckoned in two series of 12, one series from midnight to noon and the second from noon to midnight, but sometimes reckoned in one series of 24, from midnight to midnight.

   He slept for the hour between 2 and 3 a.m. The hour for the bombardment was between 1300 and 1400.

3. any specific time of day; the time indicated by a timepiece.

   What is the hour?

4. a short or limited period of time.

   He savored his hour of glory.

5. a particular or appointed time.

   What was the hour of death? At what hour do you open?

6. a customary or usual time.

   When is your dinner hour?

7. the present time.

   The magazine had an interview with the man of the hour, star of the hottest new superhero movie.

8. hours,

   1. time spent in an office, factory, or the like, or for work, study, etc..

      The doctor's hours were from 10 to 4. What employees do after hours is their own business.

   2. customary time of going to bed and getting up.

      Actors often keep late hours.

   3. (in the Christian church) the seven stated times of the day for prayer and devotion.

   4. the offices or services prescribed for the seven stated times of the day for prayer and devotion.

   5. a book containing the seven stated times of the day for prayer and devotion.

9. distance normally covered in an hour's traveling.

   We live about an hour from the city.

10. Astronomy. a unit of measure of right ascension representing 15°, or the twenty-fourth part of a great circle.

11. a single period, as of class instruction or therapeutic consultation, usually lasting from 40 to 55 minutes.

12. Also called credit hour.  Education. one unit of academic credit, usually representing attendance at one scheduled period of instruction per week throughout a semester, quarter, or term.

13. Classical Mythology. the Hours, the Horae.

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adjective

1. of, relating to, or noting an hour.

idioms

1. one's hour,

   1. Also one's last hour. the instant of death.

      The sick man knew that his hour had come.

   2. any crucial moment.

hour British  

/ aʊə /

noun

1. a period of time equal to 3600 seconds; 1/ 24 th of a calendar day

2. any of the points on the face of a timepiece that indicate intervals of 60 minutes

3. an exact number of complete hours

   the bus leaves on the hour

4. the time of day as indicated by a watch, clock, etc

5. the period of time allowed for or used for something

   the lunch hour

   the hour of prayer

6. a special moment or period

   our finest hour

7. the present time

   the man of the hour

8. the distance covered in an hour

   we live an hour from the city

9. astronomy an angular measurement of right ascension equal to 15° or a 24th part of the celestial equator

10. 1. a time of success, fame, etc

    2. Also: one's last hour.  the time of one's death

       his hour had come

11. informal to do something in a leisurely manner

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hour Scientific  

/ our /

1. A unit of time equal to one of the 24 equal parts of a day; 60 minutes.

2. ◆ A sidereal hour is 1/24 of a sidereal day, and a mean solar hour is 1/24 of a mean solar day.

3. See more at sidereal time solar time

4. A unit of measure of longitude or right ascension, equal to 15° or 1/24 of a great circle.

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hour More Idioms  

1. see after hours; all hours; by the day (hour); eleventh hour; happy hour; keep late hours; on the hour; small hours.

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Other Word Forms

• hourless adjective

Etymology

Origin of hour

First recorded in 1175–1225; Middle English (h)oure from Anglo-French; Old French (h)ore, from Latin hōra, from Greek hṓrā “time, season”

Explanation

An hour is a unit of time — it's sixty minutes, 3,600 seconds, or the length it takes the long hand on your watch to move in a full circle. If your math class lasts an hour, it might start at 9:30 and end at 10:30, one hour later. Hour also means "time of day." If your phone rings at two a.m., you could ask, "Why are you calling at such a late hour, Mom?" The word stems from the Old French hore, "one-twelfth of a day," with its roots in the Latin hora, "hour" or "season," and Greek hora, "the season."

Example Sentences

Recently the UK government announced new guidance which states children under the age of five should be limited to one hour of screen time a day, while under-twos should not be watching screens alone.

From BBC • Apr. 10, 2026

The change adds about an hour of flight time and an extra, fuel-intensive takeoff from Changi Airport.

From The Wall Street Journal • Apr. 10, 2026

A team of nearly 50 supported operations during the festival as the astronaut roved the grounds at a speed of less than five miles an hour.

From Los Angeles Times • Apr. 10, 2026

It decelerates the vehicle from about 350 miles per hour to about 17 miles per hour for a nice soft landing for the crew in the Pacific Ocean.

From Barron's • Apr. 10, 2026

We must have been out here for an hour or more.

From "The Brightwood Code" by Monica Hesse

Related Words

• age
• date
• day
• era
• future
• generation
• life
• moment
• month
• occasion
• pace
• past
• point
• present
• season
• second
• space
• stage
• term
• turn