moon

¹

[ moon ]

noun

1. none the moon or the Moon, the earth's natural satellite, orbiting the earth at a mean distance of 238,857 miles (384,393 km) and having a diameter of 2,160 miles (3,476 km).
2. this body during a particular lunar month, or during a certain period of time, or at a certain point of time, regarded as a distinct object or entity. Compare full moon ( def 1 ), half-moon ( def 1 ), new moon ( def 1 ), waning moon ( def ), waxing moon ( def ).
3. a lunar month, or, in general, a month.
4. any planetary satellite:

   the moons of Jupiter.

5. something shaped like an orb or a crescent.
6. moonlight ( def 1 ).
7. a platyfish.
8. Slang. the buttocks, especially when bared.

verb (used without object)

1. to act or wander abstractedly or listlessly:

   You've been mooning about all day.

2. to sentimentalize or remember nostalgically:

   He spent the day mooning about his lost love.

3. to gaze dreamily or sentimentally at something or someone:

   They sat there mooning into each other's eyes.

4. Slang. to expose one's buttocks suddenly and publicly as a prank or gesture of disrespect.

verb (used with object)

1. to spend (time) idly:

   She mooned the afternoon away, unable to think what to do next.

2. to illuminate by or align against the moon.
3. Slang. to expose one's buttocks to as a prank or gesture of disrespect.

Moon

²

[ moon ]

noun

1. Sun Myung [suhn myuhng], 1920–2012, Korean religious leader: founder of the Unification Church.

Moon

¹

/ muːn /

noun

1. MoonWilliam18181894MBritishTECHNOLOGY: inventorWRITING: printer William. 1818–94, British inventor of the Moon writing system in 1847, who, himself blind, taught blind children in Brighton and printed mainly religious works from stereotyped plates of his own designing

Moon

²

/ muːn /

noun

1. See Braille
   a system of embossed alphabetical signs for blind readers, the fourteen basic characters of which can, by rotation, mimic most of the letters of the Roman alphabet, thereby making learning easier for those who learned to read before going blind Compare Braille 1

moon

³

/ muːn /

noun

1. sometimes capital the natural satellite of the earth. Diameter: 3476 km; mass: 7.35 × 10 ²²kg; mean distance from earth: 384 400 km; periods of rotation and revolution: 27.32 days lunar
2. the face of the moon as it is seen during its revolution around the earth, esp at one of its phases

   new moon

   full moon

3. any natural satellite of a planet
4. moonlight; moonshine
5. something resembling a moon
6. a month, esp a lunar one
7. once in a blue moon
   once in a blue moon very seldom
8. over the moon informal.
   over the moon extremely happy; ecstatic
9. reach for the moon
   reach for the moon to desire or attempt something unattainable or difficult to obtain

verb

1. whentr, often foll by away; when intr, often foll by around to be idle in a listless way, as if in love, or to idle (time) away
2. slang.
   intr to expose one's buttocks to passers-by

moon

/ mo̅o̅n /

1. Often Moon. The natural satellite of Earth, visible by reflection of sunlight and traveling around Earth in a slightly elliptical orbit at an average distance of about 381,600 km (237,000 mi). The Moon's average diameter is 3,480 km (2,160 mi), and its mass is about 1 80 that of Earth. Its average period of revolution around Earth is 29 days, 12 hours, 44 minutes.
2. See more at giant impact theory
3. A natural satellite revolving around a planet.

moon

1. A natural satellite of a planet ; an object that revolves around a planet. The planets vary in the number of their moons; for example, Mercury and Venus have none, the Earth has one, and Jupiter has seventeen or more. The planets' moons, like the planets themselves, shine by reflected light .

Notes

The Earth's moon is about 240,000 miles away and is about 2,000 miles in diameter. The volume of the Earth is fifty times that of the moon; the mass of the Earth is about eighty times that of the moon. The moon has no atmosphere , and its gravity is about one-sixth that of the Earth.

Derived Forms

• ˈmoonless, adjective

Other Words From

• moon·er noun
• moon·less adjective

Word History and Origins

Origin of moon¹

First recorded before 900; Middle English mone, Old English mōna; cognate with Old High German māno, Old Norse māni, Gothic mena; akin to German Mond “moon,” Latin mēnsis “month,” Greek mḗnē “moon,” Sanskrit māsa “moon, month”

Word History and Origins

Origin of moon¹

Old English mōna; compare Old Frisian mōna, Old High German māno

A Closer Look

The Earth's Moon is a desolate and quiet place. The only natural satellite of Earth, it consists almost entirely of rock, shows no signs of ongoing geologic activity, has no water, and has a very thin atmosphere consisting primarily of sodium. But our Moon does not present a typical case for planetary satellites. Over the last 50 years, over a hundred more moons have been discovered in the solar system, so that they now total 165, nearly all of them orbiting the larger planets Jupiter, Saturn, and Uranus (Mercury and Venus have no moon), with an additional four moons orbiting dwarf planets. Because they are so far from the Sun, these moons are for the most part extremely cold. Io, one of Jupiter's 63 known moons, is an exception. It is the most geologically active body in the solar system, with almost constant volcanic activity and a surface covered by cooling lava. Some scientists think that another moon of Jupiter, Europa, may have liquid water capable of supporting life underneath a thick layer of surface ice. Titan, one of Saturn's moons, may also be capable of supporting primitive life in the ocean of liquid methane on its frigid surface.

Idioms and Phrases

Idioms

1. blue moon. blue moon.
2. over the moon. over the moon.

More idioms and phrases containing moon

see ask for the moon ; once in a blue moon .

Example Sentences

Next year, NASA will decide whether to go forward with one or more of the teams in the hopes of returning humans to the moon by 2024 as part of the Artemis program.

From Fortune

“It’s safer for Hubble to observe sunlight reflected off the moon” than to look directly at the backlit Earth, explains Allison Youngblood, an astronomer at the University of Colorado Boulder.

From Science News

Laplace wondered to what degree the moon gravitationally squeezes the air surrounding our planet, and he set out to analyze the types of waves that might emerge as a consequence.

From Quanta Magazine

Meticulous instructions are submitted by astronomers ahead of time, and observations are loaded into a telescope “queue” that can take into account weather, moon phases and atmospheric conditions.

From Quanta Magazine

Researchers searching for life on other planets or moons are bound to face the same problem.

From Quanta Magazine

There is an expanded place-name index with more than 150,000 entries, and separate undersea, Moon, and Mars features.

From The Daily Beast

What would it take to carry people to the Moon, or Mars, or an asteroid?

From The Daily Beast

Many Sailor Moon story arcs, in the comics and on television, end with the Sailor Senshi dying and being reborn.

From The Daily Beast

Sailor Moon Crystal is expected to wrap up its initial storylines by the end of the year.

From The Daily Beast

Still, Sailor Moon fans are always ravenous for new content, especially after such a long time away.

From The Daily Beast

The moon seemed to smile on him; the aurora appeared to dance with unwonted vigour, as if in glee; the very stars winked at him!

From Project Gutenberg

It had been many a moon since we took different roads, but MacRae hadn't changed that I could see.

From Project Gutenberg

The moon rose on a terrified mob trudging or riding the forty miles of road between Meerut and the Mogul capital.

From Project Gutenberg

He had thought what it would be like to be a rich man, and bring a certain girl here for a moon of honey and roses.

From Project Gutenberg

The storm, however, was over; the moon and stars were shining in a clear sky, and the aurora was dancing merrily.

From Project Gutenberg