day

noun

ˈdā 

plural days

1

a

: 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 plural

the old days

the 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.

see also:

call it a day carry the day day after day day in and day out see the light of day

Synonyms of day

• daytime
• daylight
• afternoon
• morning

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.

Recent Examples on the Web

In a broad open field, horses munch standing hay as Katie Baltzor watches her black angus cattle on this fall day. — Anna King, NPR, 25 Oct. 2026

After a quiet day otherwise, Riley exploded for 33- and 72-yard rushing touchdowns to finish as the game’s leading rusher with 128 yards and two touchdowns on 13 carries. — Shaun Goodwin, Idaho Statesman, 25 Oct. 2026

Obama, campaigning for el Sayed in Detroit just 10 days before Election Day, acknowledged the Democratic Michigan Senate candidate does not agree with him on every issue. — Barnini Chakraborty, The Washington Examiner, 25 Oct. 2026

The Equal Employment Opportunity Commission, which enforces antidiscrimination laws, also enforces a 180-day window for filing a complaint, but that can be extended to 300 days in cases covered by a state or local anti-discrimination law. — ABC News, 24 Oct. 2026

Word History

Etymology

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

First Known Use

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

Phrases Containing day

• a day
• a day to remember
• all-day
• all in a day's work
• (all) the livelong day
• any day now
• any old day
• as clear as day/daylight/anything
• (as) plain as day
• at all hours of the day
• at the end of the day
• bad hair day
• bluebird day
• break of day
• business day
• by day
• by the day
• call it a day
• can't wait all day
• carry the day
• catch of the day
• day after day
• day by day
• day camp
• day care
• day in and day out
• day in, day out
• day is breaking
• day job
• day laborer
• day letter
• day/moment/time in the sun
• day-neutral
• day nursery
• day one
• day pass
• day return
• day school
• day student
• day to day
• day trader
• day trip
• day-tripper
• day worker
• D-day
• degree-day
• dollar day
• don't have all day
• dress-down day
• early day
• ember day
• every dog has his/its day
• family day
• fast day
• field day
• first day cover
• flag day
• for a rainy day
• from day to day
• from one day to the next
• from that day forth
• from that day forth/forward
• game day
• give (someone) the time of day
• good day
• groundhog day
• have a field day
• have a good day
• have a nice day
• haven't got all day
• have one's day in court
• high day
• holy day
• holy day of obligation
• hump day
• if he/she is day
• in one's day
• in the cold light of day
• in this day and age
• it is not every day
• judgment day
• late in the day
• latter-day
• Latter-day Saint
• lay day
• live to see the day
• long-day
• Lord's day
• lucky day
• make a day/night/morning/afternoon/evening of it
• make someone's day
• man-day
• M-day
• mean solar day
• mental health day
• modern-day
• name day
• night and day
• not give (someone) the time of day
• not look a day over
• of the day
• on a day-to-day basis
• one day
• on the day
• open day
• order of the day
• pass the time of day
• polling day
• present-day
• quarter day
• queen for a day agreement
• queen for a day letter
• rainy day
• rainy day fund
• red-letter day
• rue the day
• saint's day
• save the day
• see the day
• see the light of day
• seize the day
• short-day
• sick day
• sidereal day
• slow news day
• snow day
• solar day
• someone's day
• speech day
• sports day
• take a/the day off
• take each day as it comes
• take it/things day by day
• take it/things one day at a time
• take one day at a time
• that'll be the day
• the big day
• the day before yesterday
• the heat of the day
• the order of the day
• the other day/night/morning/afternoon/evening
• the present day
• today's the day
• to the day
• to this day
• twenty-four hours a day
• twice a day
• until one's dying day
• V-day
• working day
• zero-day

Rhymes for day

• ay
• bay
• bey
• brae
• cay
• chez
• dey
• dray
• fay
• fey
• flay
• fray

Kids Definition

day

noun

ˈdā 

1

a

: the time of light between one night and the next

b

: daylight

2

a

: the time the earth takes to make one turn on its axis

b

: the time required for a heavenly body to turn once on its axis

a lunar day

3

: a period of 24 hours beginning at midnight

4

: a specified day or date

the day of the picnic

their wedding day

5

: a specified time or period : age

in grandmother's day

6

: the conflict or dispute of the day

fought hard and won the day

7

: the time set apart by custom or law for work

the eight-hour day

Biographical Definition

Day 1 of 3

biographical name (1)

ˈdā 

Clarence Shepard, Jr. 1874–1935 American author

Day

2 of 3

biographical name (2)

Thomas 1748–1789 English author

Day

3 of 3

biographical name (3)

William Rufus 1849–1923 American statesman and jurist