Moon

UK: /ˈmuːn/ US: /mun/ ,(mo̅o̅n)

Collins Concise English Dictionary © HarperCollins Publishers::

Moon / 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 Braille1

Moon / 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

WordReference Random House Learner's Dictionary of American English © 2025

moon /mun/   n. 

[countable]
1. Astronomy [singular* the + ~] the earth's natural satellite.
2. Astronomy a natural satellite that goes around any planet:
   the moons of Jupiter.

v. [no object]

3. to act or wander dreamily or without energy:
   He's been mooning about her all day.

Idioms

4. blue moon, a very long time:
   Once in a blue moon such a chance comes along.

WordReference Random House Unabridged Dictionary of American English © 2025

moon  (mo̅o̅n), n. 

1. Astronomy 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).
2. Astronomy 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. Cf. full moon, half-moon, new moon, waning moon, waxing moon. 
3. a lunar month, or, in general, a month.
4. Astronomy any planetary satellite:
   the moons of Jupiter.
5. something shaped like an orb or a crescent.
6. moonlight.
7. Fish a platyfish.
8. Slang Terms the buttocks, esp. when bared.
9. Idioms blue moon, a very long period of time:
   Such a chance comes once in a blue moon.

v.i. 

10. to act or wander abstractedly or listlessly:
    You've been mooning about all day.
11. to sentimentalize or remember nostalgically:
    He spent the day mooning about his lost love.
12. to gaze dreamily or sentimentally at something or someone:
    They sat there mooning into each other's eyes.
13. Slang Terms to expose one's buttocks suddenly and publicly as a prank or gesture of disrespect.

v.t. 

14. to spend (time) idly:
    to moon the afternoon away.
15. to illuminate by or align against the moon.
16. Slang Terms to expose one's buttocks to as a prank or gesture of disrespect.

• bef. 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 mé̄nē moon, Sanskrit māsa moon, month

moon′er, n. 
moon′less, adj. 

Moon  (mo̅o̅n), n. 

Sun Myung  (sun myung), born 1920, Korean religious leader: founder of the Unification Church.

Collins Concise English Dictionary © HarperCollins Publishers::

moon / muːn/ noun

1. (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(s): 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. over the moon ⇒ extremely happy; ecstatic

verb

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

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

ˈmoonless adjective