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[moon] /mun/
the earth's natural satellite, orbiting the earth at a mean distance of 238,857 miles (384,393 km) and having a diameter of 2160 miles (3476 km).
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.
a lunar month, or, in general, a month.
any planetary satellite:
the moons of Jupiter.
something shaped like an orb or a crescent.
a platyfish.
Slang. the buttocks, especially when bared.
verb (used without object)
to act or wander abstractedly or listlessly:
You've been mooning about all day.
to sentimentalize or remember nostalgically:
He spent the day mooning about his lost love.
to gaze dreamily or sentimentally at something or someone:
They sat there mooning into each other's eyes.
Slang. to expose one's buttocks suddenly and publicly as a prank or gesture of disrespect.
verb (used with object)
to spend (time) idly:
to moon the afternoon away.
to illuminate by or align against the moon.
Slang. to expose one's buttocks to as a prank or gesture of disrespect.
blue moon, a very long period of time:
Such a chance comes once in a blue moon.
Origin of moon
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
Related forms
mooner, noun
moonless, adjective Unabridged
Based on the Random House Dictionary, © Random House, Inc. 2018.
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Examples from the Web for moonless
Contemporary Examples
Historical Examples
  • The building seemed to have grown larger under the moonless sky.

    L'Assommoir Emile Zola
  • It was a moonless night, thick with stars above, very dark on the water.

    Chance Joseph Conrad
  • It was indeed a moonless night, but he did not make for the highroad.

  • It was by this time in the small hours of a dark, moonless night.

    The Pirate of Panama William MacLeod Raine
  • It was a moonless night, but the sky was clear and spangled with stars.

    The Call of the Blood

    Robert Smythe Hichens
  • It was a moonless night, and a haze of cloud obscured the stars.

    Margaret Tudor Annie T. Colcock
  • It was a moonless night, but clear and brilliant with stars.

    In Mesopotamia Martin Swayne
  • It was a moonless night, and had been a dark one; but it was now close upon morning.

    The Ocean Waifs Mayne Reid
British Dictionary definitions for moonless


(sometimes capital) the natural satellite of the earth. Diameter: 3476 km; mass: 7.35 × 1022 kg; mean distance from earth: 384 400 km; periods of rotation and revolution: 27.32 days related adjective lunar
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
any natural satellite of a planet
moonlight; moonshine
something resembling a moon
a month, esp a lunar one
once in a blue moon, very seldom
(informal) over the moon, extremely happy; ecstatic
reach for the moon, to desire or attempt something unattainable or difficult to obtain
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
(intransitive) (slang) to expose one's buttocks to passers-by
Derived Forms
moonless, adjective
Word Origin
Old English mōna; compare Old Frisian mōna, Old High German māno


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 Braille1


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
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Word Origin and History for moonless

c.1500, from moon (n.) + -less.



Old English mona, from Proto-Germanic *menon- (cf. Old Saxon and Old High German mano, Old Frisian mona, Old Norse mani, Danish maane, Dutch maan, German Mond, Gothic mena "moon"), from PIE *me(n)ses- "moon, month" (cf. Sanskrit masah "moon, month;" Avestan ma, Persian mah, Armenian mis "month;" Greek mene "moon," men "month;" Latin mensis "month;" Old Church Slavonic meseci, Lithuanian menesis "moon, month;" Old Irish mi, Welsh mis, Breton miz "month"), probably from root *me- "to measure," in reference to the moon's phases as the measure of time.

A masculine noun in Old English. In Greek, Italic, Celtic, Armenian the cognate words now mean only "month." Greek selene (Lesbian selanna) is from selas "light, brightness (of heavenly bodies)." Old Norse also had tungl "moon," ("replacing mani in prose" - Buck), evidently an older Germanic word for "heavenly body," cognate with Gothic tuggl, Old English tungol "heavenly body, constellation," of unknown origin or connection. Hence Old Norse tunglfylling "lunation," tunglœrr "lunatic" (adj.).

Extended 1665 to satellites of other planets. To shoot the moon "leave without paying rent" is British slang from c.1823; card-playing sense perhaps influenced by gambler's shoot the works (1922) "go for broke" in shooting dice. The moon race and the U.S. space program of the 1960s inspired a number of coinages, including, from those skeptical of the benefits to be gained, moondoggle (cf. boondoggle). The man in the moon is mentioned since early 14c.; he carries a bundle of thorn-twigs and is accompanied by a dog. Some Japanese, however, see a rice-cake-making rabbit in the moon.



c.1600, "to expose to moonlight;" later "idle about" (1836), "move listlessly" (1848), probably on notion of being moonstruck. The meaning "to flash the buttocks" is first recorded 1968, U.S. student slang, from moon (n.) "buttocks" (1756), "probably from the idea of pale circularity" [Ayto]. See moon (n.). Related: Mooned; mooning.

Online Etymology Dictionary, © 2010 Douglas Harper
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moonless in Science

  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. See more at giant impact theory.

  2. A natural satellite revolving around a planet.

Our Living Language  : 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 138, nearly all of them orbiting the larger planets Jupiter, Saturn, and Uranus (Mercury, Venus, and Pluto have no moons, while Mars has two). 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 © 2002. Published by Houghton Mifflin. All rights reserved.
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moonless in Culture

moon definition

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.

Note: 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 Company.
Published by Houghton Mifflin Company. All rights reserved.
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Slang definitions & phrases for moonless



Cheap whiskey, esp whiskey made by unlicensed distillers; moonshine: a couple of pints of moon/ using it to transport moon (1928+)


  1. To behave in a pleasantly listless and dreamy way: I was sitting there mooning over her latest letter (1848+)
  2. To exhibit one's bare buttocks as a defiant or amusing gesture, usually out a window (1960s+ Teenagers & students)

[second noun sense fr moon, ''buttocks,'' found by 1756]

The Dictionary of American Slang, Fourth Edition by Barbara Ann Kipfer, PhD. and Robert L. Chapman, Ph.D.
Copyright (C) 2007 by HarperCollins Publishers.
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Idioms and Phrases with moonless
The American Heritage® Idioms Dictionary
Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.
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