month

UK: /ˈmʌnθ/ US: /mʌnθ/ ,(munth)

WordReference Random House Learner's Dictionary of American English © 2026

month /mʌnθ/   n. [countable]

1. Time any of the 12 parts, as January or February, into which the calendar year is divided.
2. Time the time from any day of one calendar month to the corresponding day of the next, or a period of four weeks or 30 days.

Idioms

3. Idioms a month of Sundays, any long period of time:
   It's been a month of Sundays since you've called.

WordReference Random House Unabridged Dictionary of American English © 2026

month  (munth), n. 

1. Time Also called calendar month. any of the twelve parts, as January or February, into which the calendar year is divided.
2. Time the time from any day of one calendar month to the corresponding day of the next.
3. Time a period of four weeks or 30 days.
4. Astronomy Also called solar month. one-twelfth of a solar or tropical year.
5. Astronomy 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.

• bef. 900; Middle English; Old English mōnath; cognate with Old High German mānōd, Old Norse mānathr. See moon

Collins Concise English Dictionary © HarperCollins Publishers::

month / 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. a month of Sundays ⇒ a long unspecified period

Related adjective(s): mensal

Etymology: Old English mōnath; related to Old High German mānōd, Old Norse mānathr; compare Gothic mena moon