\ˈdā \

Definition of day 

(Entry 1 of 4)

1a : the time of light between one night and the next the shortest day of the year

b : daylight sense 1 woke up at the break of day

c : daytime sleeps during the day and works at night

2 astronomy : the period of rotation of a planet (such as earth) or a moon on its axis the length of one day on Mars

3 : the mean solar day of 24 hours beginning at midnight by mean time open seven days a week the first day of every month Take one pill two times a day.

4 : a specified day or date their wedding day the day of her birth

5 : a specified time or period : age in grandfather's day often used in plural the old daysthe days of sailing ships

6 : the conflict or contention of the day played hard and won the day

7 : the time established by usage or law for work, school, or business starts his day with a cup of coffee after a long day at school We have a busy day tomorrow.

day after day

: for an indefinite or seemingly endless number of days wore the same pants day after day

day in, day out

: for an indefinite number of successive days does the same thing at work day in, day out


biographical name (1)
\ˈdā \

Definition of Day (Entry 2 of 4)

Clarence Shepard, Jr. 1874–1935 American author


biographical name (2)

Definition of Day (Entry 3 of 4)

Thomas 1748–1789 English author


biographical name (3)

Definition of Day (Entry 4 of 4)

William Rufus 1849–1923 American statesman and jurist

Keep scrolling for more

Synonyms & Antonyms for day

Synonyms: Noun

daylight, daytime

Antonyms: Noun

night, nighttime

Visit the Thesaurus for More 

Examples of day in a Sentence


We're open seven days a week, 365 days a year. Payment is due on the first day of every month. “What day of the week is the 28th?” “It's a Friday.” He spent five days in the hospital. She left on Thursday and came back four days later. That was the happiest day of my life. Parenthood gets better every day. The office is closed for the day. She works eight hours a day. It costs 10 dollars a day to park there.
See More

Recent Examples on the Web: Noun

Getting into a meditation groove takes practice, which means doing it every single day. Gigi Engle, SELF, "How to Get Really Comfortable in Your Body for Sex," 8 Dec. 2018 Then came the maintenance phase: 300 mg every day for another 24 weeks. Cathleen O'grady, Ars Technica, "Some promising news for kids with peanut allergies," 23 Nov. 2018 Above the fold The company has made no secret of its plans to create a folding smartphone, and Samsung executives have consistently teased the developers conference keynote, which starts at 10 a.m. PST, as the big day. Michael Simon, PCWorld, "Unless Samsung is trolling us, a folding Galaxy phone is finally coming this week," 5 Nov. 2018 That was the same day Khashoggi, a columnist for The Washington Post who wrote critically of Prince Mohammed's rise to power, entered the consulate and was not seen again. Suzan Fraser, Fox News, "Man linked to Saudi prince at consulate when writer vanished," 18 Oct. 2018 Deb Haaland wears the same pearl necklace almost every day. Jessica Militare, Glamour, "Deb Haaland Is One of the First Native American Congresswomen. It Only Took Two Centuries.," 9 Nov. 2018 Attendees will have the option to experience one or both days of Summit programming: Friday Career Immersions ($199), Saturday Summit ($349), or All-Access: Friday Career Immersions and Saturday Summit ($499). Teen Vogue Staff, Teen Vogue, "How to Get Tickets for the Teen Vogue Summit Los Angeles 2018," 9 Nov. 2018 For most of that first day home, his cat sat in his lap, purring and looking up at him in total adoration. Lindsey Vehlewald, SELF, "We Never Got Flu Shots. Then the Flu Almost Killed My Husband," 9 Nov. 2018 Those pieces, while architecturally striking, aren’t necessarily fit for the streets of Los Angeles—you’d be hard-pressed to find someone dressed in something that fussy on a sunny day in the City of Angels. Rachel Hahn, Vogue, "In Her New Music Video, Kelsey Lu’s Wardrobe Is Even More Stunning Than the L.A. Landscape," 9 Nov. 2018

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'day.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

See More

First Known Use of day


before the 12th century, in the meaning defined at sense 1a

History and Etymology for day


Middle English, from Old English dæg; akin to Old High German tag day

Keep scrolling for more

Learn More about day

Dictionary Entries near day






day's duty

day's work

Statistics for day

Last Updated

11 Dec 2018

Look-up Popularity

Time Traveler for day

The first known use of day was before the 12th century

See more words from the same century

Keep scrolling for more

More Definitions for day



English Language Learners Definition of day

: a period of 24 hours beginning at midnight : one of the seven time periods that make up a week

: the time of light between one night and the next : the part of the day when light from the sun can be seen

: the part of the day when people are usually most active and when most businesses are open


\ˈdā \

Kids Definition of day

1 : the time between sunrise and sunset : daylight

2 : the time a planet or moon takes to make one turn on its axis A day on earth lasts 24 hours.

3 : a period of 24 hours beginning at midnight The offer expires in ten days.

4 : a specified day or date Tuesday is Election Day.

5 : a particular time : age There was no Internet in your grandparent's day.

6 : the time set apart by custom or law for work He works an eight-hour day.

Keep scrolling for more

More from Merriam-Webster on day

Rhyming Dictionary: Words that rhyme with day

Thesaurus: All synonyms and antonyms for day

Spanish Central: Translation of day

Nglish: Translation of day for Spanish Speakers

Britannica English: Translation of day for Arabic Speakers Encyclopedia article about day

Comments on day

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


a soft lustrous wool fabric with mohair

Get Word of the Day daily email!

Test Your Vocabulary

Late Autumn 2018 Words of the Day Quiz

  • frosted-autumn-leaves
  • Which is a synonym of yahoo?
Name That Thing

Test your visual vocabulary with our 10-question challenge!

Word Winder's CrossWinder

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


Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!