1
a
often capitalized
: the earth's natural satellite (see satellite sense 1a) that shines by the sun's reflected light, revolves about the earth from west to east in about 29¹/₂ days with reference to the sun or about 27¹/₃ days with reference to the stars, and has a diameter of 2160 miles (3475 kilometers), a mean distance from the earth of about 238,900 miles (384,400 kilometers), and a mass about one eightieth that of the earth
—usually used with the
b
: one complete moon cycle consisting of four phases (see phase entry 1 sense 1)
c
: satellite sense 1
specifically
: a natural satellite of a planet
the moons of Jupiter
2
: an indefinite usually extended period of time
a labor of many moons
3
: moonlight
keep out of the moon or it may turn your head—
H. R. Haggard
H. R. Haggard4
: something that resembles a moon: such as
a
: a highly translucent (see translucent sense 1) spot on old porcelain
b
: lunule
c
slang
: naked buttocks
5
: something impossible or inaccessible
reach for the moon
mooned; mooning; moons
1
: to spend in idle reverie : dream
—used with away
mooned the afternoon away
2
slang
: to expose one's naked buttocks to
One of the boys mooned the crowd.
: to spend time in idle reverie : behave abstractedly
fans mooning over movie stars
Examples of moon in a Sentence
Noun
The telescope makes the craters on the surface of the moon incredibly clear.
the orbit of the Moon around the Earth
Europa and Io are both moons of Jupiter.
a planet orbited by one moon
Verb
One of the boys mooned the crowd.
One of the boys mooned at the crowd.
Recent Examples on the Web
Usa Today, USA Today, 27 June 2025
Believe in your skills, talents, and resources as a new six-month cycle begins under the new moon in Leo two days later.
—Liz Simmons, StyleCaster, 24 June 2025
Issy Van Der Velde, Rolling Stone, 5 Apr. 2025
In this week’s Rover Report, Curiosity is making tracks towards Mount Sharp while getting mooned.
—IEEE Spectrum, 23 Aug. 2013
See All Example Sentences for moon
Examples are automatically compiled from online sources to
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Noun
Your emotional foundation may get rocked during today’s Leo moon.
—Usa Today, USA Today, 27 June 2025
Believe in your skills, talents, and resources as a new six-month cycle begins under the new moon in Leo two days later.
—Liz Simmons, StyleCaster, 24 June 2025
Verb
Rather than aiming for photorealism, everything in Minecraft, from the ground to the trees to the animals to the sun and moon themselves, is represented by large, chunky blocks.
—Issy Van Der Velde, Rolling Stone, 5 Apr. 2025
In this week’s Rover Report, Curiosity is making tracks towards Mount Sharp while getting mooned.
—IEEE Spectrum, 23 Aug. 2013
See All Example Sentences for moon
Cite this Entry
“Moon.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/moon. Accessed 12 Jul. 2025.
Copy CitationKids Definition
moon
1 of 2 noun1
a
: the earth's natural satellite that shines by reflecting light from the sun and revolves about the earth in about 29½ days
2
: an unspecified and usually long period of time
took many moons to complete
moonless
adjective
-ləs
moon
2 of 2 verb
: to spend time daydreaming
Medical Definition
moon
nounLove words? Need even more definitions?
Merriam-Webster unabridged
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