moon

[ moon ]
See synonyms for moon on Thesaurus.com
noun
  1. 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, waxing moon.

  1. a lunar month, or, in general, a month.

  2. any planetary satellite: the moons of Jupiter.

  3. something shaped like an orb or a crescent.

  4. 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.

  1. to gaze dreamily or sentimentally at something or someone: They sat there mooning into each other's eyes.

  2. 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.

  1. Slang. to expose one's buttocks to as a prank or gesture of disrespect.

Idioms about moon

  1. blue moon. See entry at blue moon.

  2. over the moon. See entry at over the moon.

Origin of moon

1
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”

Other words from moon

  • moon·er, noun
  • moon·less, adjective

Other definitions for Moon (2 of 2)

Moon
[ moon ]

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

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2024

British Dictionary definitions for moon (1 of 3)

moon

/ (muːn) /


noun
  1. (sometimes capital) the natural satellite of the earth. Diameter: 3476 km; mass: 7.35 × 10 22 kg; mean distance from earth: 384 400 km; periods of rotation and revolution: 27.32 days: Related adjective: 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

  1. any natural satellite of a planet

  2. moonlight; moonshine

  3. something resembling a moon

  4. a month, esp a lunar one

  5. once in a blue moon very seldom

  6. over the moon informal extremely happy; ecstatic

  7. reach for the moon to desire or attempt something unattainable or difficult to obtain

verb
  1. (when tr, 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. (intr) slang to expose one's buttocks to passers-by

Origin of moon

1
Old English mōna; compare Old Frisian mōna, Old High German māno

Derived forms of moon

  • moonless, adjective

British Dictionary definitions for Moon (2 of 3)

Moon1

/ (muːn) /


noun
  1. 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

British Dictionary definitions for Moon (3 of 3)

Moon2

/ (muːn) /


noun
  1. 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

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Scientific definitions for moon

moon

[ mōōn ]


  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 180 that of Earth. Its average period of revolution around Earth is 29 days, 12 hours, 44 minutes. See more at giant impact theory.

  2. A natural satellite revolving around a planet.

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.

The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

Cultural definitions for moon

moon

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 for moon

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.

The New Dictionary of Cultural Literacy, Third Edition Copyright © 2005 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

Other Idioms and Phrases with moon

moon

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

The American Heritage® Idioms Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.