month

American  

[muhnth] / mʌnθ /

noun

months plural

1. Also called calendar month.  any of the twelve parts, as January or February, into which the calendar year is divided.

2. the time from any day of one calendar month to the corresponding day of the next.

3. a period of four weeks or 30 days.

4. Also called solar month.  one-twelfth of a solar or tropical year.

5. Also called lunar month.  the period of a complete revolution of the moon around the earth, as the period between successive new moons synodic month, equal to 29.531 days, or the period between successive conjunctions with a star sidereal month, equal to 27.322 days, or the period between successive perigees anomalistic month, equal to 27.555 days, or the period between successive similar nodes nodical month, or draconic month, equal to 27.212 days.

6. an unusually long period of time of indefinite length.

   I haven't seen him for months.

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idioms

1. a month of Sundays. Sunday.

month British  

/ mʌnθ /

noun

1. one of the twelve divisions ( calendar months ) of the calendar year

2. a period of time extending from one date to a corresponding date in the next calendar month

3. a period of four weeks or of 30 days

4. the period of time ( tropical month ) taken by the moon to return to the same longitude after one complete revolution around the earth; 27.321 58 days (approximately 27 days, 7 hours, 43 minutes, 4.5 seconds)

5. the period of time ( sidereal month ) taken by the moon to make one complete revolution around the earth, measured between two successive conjunctions with a distant star; 27.321 66 days (approximately 27 days, 7 hours, 43 minutes, 11 seconds)

6. Also called: lunation.  the period of time ( lunar or synodic month ) taken by the moon to make one complete revolution around the earth, measured between two successive new moons; 29.530 59 days (approximately 29 days, 12 hours, 44 minutes, 3 seconds)

7. informal a long unspecified period

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month More Idioms  

More idioms and phrases containing month

• (for months) on end
• by the day (month)

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Other Word Forms

Noun Inflected Forms

• months
  plural

Etymology

Origin of month

First recorded before 900; Middle English; Old English mōnath; cognate with Old High German mānōd, Old Norse mānathr. See moon

Explanation

A year is divided into twelve months, starting with January and ending with December. If it takes you a month to read a book, it takes approximately thirty days. A month is a unit of time that corresponds to the phases of the moon — which is the reason the word month, which comes from the Proto-Germanic menoth, is closely related to the word moon, whose root is menon. People have kept track of days this way since Paleolithic times, and even those who don't use the Gregorian, twelve-month calendar, still divide a year into months based on the moon.

Example Sentences

Inflation fell to 2.8% in June, increasing the likelihood that the European Central Bank will hold rates steady later this month.

From The Wall Street Journal • Jul. 9, 2026

He and Saracens' teenage try-scoring sensation Caluori both appeared in a non-cap match against a France XV in Vannes last month, but are yet to make their Test debuts.

From BBC • Jul. 9, 2026

The first meeting of negotiators is expected this month.

From Barron's • Jul. 9, 2026

In those months the strategy’s average loss was 44.3%, which is huge over any period, much less one month.

From MarketWatch • Jul. 9, 2026

Only a month or two before this, Marlene’s mother had become sick, and had died quite suddenly.

From "An Elephant in the Garden" by Michael Morpurgo

Related Words

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