Merriam-Webster Logo
  • Dictionary
  • Thesaurus
  • Scrabble
  • Spanish Central
  • Learner's Dictionary


noun \ˈau̇(-ə)r\

Simple Definition of hour

  • : one of the 24 equal parts of a day : 60 minutes

  • : the time shown on a clock or watch

  • : a particular time during the day

Source: Merriam-Webster's Learner's Dictionary

Full Definition of hour

  1. 1 :  a time or office for daily liturgical devotion; especially :  canonical hour

  2. 2 :  the 24th part of a day :  60 minutes

  3. 3 a :  the time of day reckoned in two 12-hour periods b plural :  the time reckoned in one 24-hour period from midnight to midnight using a 4-digit number of which the first two digits indicate the hour and the last two digits indicate the minute <in the military 4:30 p.m. is called 1630 hours>

  4. 4 a :  a customary or particular time <lunch hour> <in our hour of need>; also :  moment 1b <hero of the hour> b plural :  time of going to bed <keeps late hours>; also :  time of working <banker's hours>

  5. 5 :  an angular unit of right ascension equal to 15 degrees measured along the celestial equator

  6. 6 :  the work done or distance traveled at normal rate in an hour <the city was two hours away>

  7. 7 a :  a class session b :  credit hour, semester hour

after hours
  1. :  after the regular quitting or closing time

Examples of hour in a sentence

  1. She wasn't supposed to eat for six hours before the operation.

  2. You'll be paid by the hour for this job.

  3. The job pays ten dollars an hour.

  4. She exercises for a full hour every day.

  5. She was half an hour late.

  6. They arrived a few hours later.

  7. The project required long hours of work.

  8. The mood changed from hour to hour.

  9. These animals are most active in the hour just before sunrise.

  10. You can call me at any hour of the day or night.

Origin of hour

Middle English, from Anglo-French ure, eure, from Late Latin & Latin; Late Latin hora canonical hour, from Latin, hour of the day, from Greek hōra — more at year

First Known Use: 13th century

Other Weights and Measures Terms

HOUR Defined for Kids


noun \ˈau̇r\

Definition of hour for Students

  1. 1 :  one of the 24 divisions of a day :  60 minutes

  2. 2 :  the time of day <The hour is now half past five.>

  3. 3 :  a fixed or particular time <school hours> <He helped in our hour of need.>

  4. 4 :  the distance that can be traveled in an hour <She lives three hours from here.>

Seen and Heard

What made you want to look up hour? Please tell us where you read or heard it (including the quote, if possible).


expressing little or no emotion

Get Word of the Day daily email!


Take a 3-minute break and test your skills!

Name That Thing

Test your visual vocabulary with our 10-question challenge!


Test Your Knowledge - and learn some interesting things along the way.