hour

noun

ˈau̇(-ə)r 

1

: a time or office for daily liturgical devotion

especially : canonical hour

2

: the 24th part of a day : 60 minutes

3

a

: the time of day reckoned in two 12-hour periods

b

hours 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

a

: a customary or particular time

lunch hour

in our hour of need

also : moment sense 1b

hero of the hour

b

hours plural : time of going to bed

keeps late hours

also : time of working

banker's hours

5

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

6

: the work done or distance traveled at normal rate in an hour

the city was two hours away

7

a

: a class session

b

: credit hour, semester hour

see also:

after hours

Examples of hour in a Sentence

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

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

The job pays ten dollars an hour.

She exercises for a full hour every day.

She was half an hour late.

They arrived a few hours later.

The project required long hours of work.

The mood changed from hour to hour.

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

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

Recent Examples on the Web

Fixes for what are believed to be uncommonly severe vulnerabilities are scheduled to drop in a little more than 12 hours for PHP, a programming language that powers websites and Web applications everywhere. — Dan Goodin, ArsTechnica, 21 Oct. 2026

Already postponed 24 hours, the invasion proceeded in the face of rough seas, strong winds, and low visibility in order to seize a small window in time of enormous consequence. — Marc E. Andersen, Washington Post, 21 Oct. 2026

Boeing said the program included 1,000 ground test hours, tens of thousands of pages of documentation and formal reviews with the FAA. — Neetika Walter, Interesting Engineering, 21 Oct. 2026

The mattress was ready to sleep on just a few hours after unpacking. — Nashia Baker, Architectural Digest, 21 Oct. 2026

Word History

Etymology

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, in the meaning defined at sense 1

Phrases Containing hour

• after the hour
• ampere-hour
• amp-hour
• an/per hour
• at any hour
• at the top of the hour
• before the hour
• canonical hour
• cocktail hour
• coffee hour
• credit hour
• eleventh hour
• every hour on the hour
• half an hour
• half hour
• happy hour
• H hour
• hour angle
• hour circle
• hour hand
• hour-long
• hour of need
• hour of reckoning
• kilowatt-hour
• lunch hour
• man-hour
• off-hour
• on the half hour
• on the hour
• past the hour
• person-hour
• quarter hour
• rush hour
• semester hour
• sidereal hour
• the appointed hour
• the midnight hour
• the witching hour
• unearthly hour/time
• ungodly hour
• waking hour/moment
• watt-hour
• with each passing hour
• zero hour

Rhymes for hour

• airpower
• brainpower
• devour
• empower
• firepower
• horsepower
• manpower
• mayflower
• safflower
• sunflower
• wallflower
• watchtower

Kids Definition

hour

noun

ˈau̇(ə)r 

1

: a time for or rite of religious worship

2

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

3

: the time of day

the hour is now 10:00 a.m.

4

: a fixed or particular time

lunch hour

an hour of need

5

: the distance traveled in an hour

lives two hours away

6

: a class session

I have math this hour