1.  The celestial orb which revolves round the earth; the satellite of the earth; a secondary planet, whose light, borrowed from the sun, is reflected to the earth, and serves to dispel the darkness of night. The diameter of the moon is 2,160 miles, its mean distance from the earth is 240,000 miles, and its mass is one eightieth that of the earth. See Lunar month, under Month. [1913 Webster]
"The crescent moon, the diadem of night." [1913 Webster]

2.  A secondary planet, or satellite, revolving about any member of the solar system; as, the moons of Jupiter or Saturn. [1913 Webster]

3.  The time occupied by the moon in making one revolution in her orbit; a month. Shak. [1913 Webster]

4.  A crescentlike outwork. See Half-moon. [1913 Webster]

5.  The deliberately exposed naked buttocks. [PJC]

1.  To expose to the rays of the moon. [1913 Webster]
"If they have it to be exceeding white indeed, they seethe it yet once more, after it hath been thus sunned and mooned." [1913 Webster]

2.  To expose one's naked buttocks to (a person); -- a vulgar sign of contempt or disrespect, sometimes done as a prank. [PJC]

   To act if moonstruck; to wander or gaze about in an abstracted manner. [1913 Webster]
"Elsley was mooning down the river by himself." [1913 Webster]

moon, n. & v.
--n.
1 a the natural satellite of the earth, orbiting it monthly, illuminated by the sun and reflecting some light to the earth. b this regarded in terms of its waxing and waning in a particular month (new moon). c the moon when visible (there is no moon tonight).
2 a satellite of any planet.
3 (prec. by the) something desirable but unattainable (promised them the moon).
4 poet. a month.
--v.
1 intr. (often foll. by about, around, etc.) move or look listlessly.
2 tr. (foll. by away) spend (time) in a listless manner.
3 intr. (foll. by over) act aimlessly or inattentively from infatuation for (a person).

Idiom:
moon boot a thickly-padded boot designed for low temperatures. moon-faced having a round face. over the moon extremely happy or delighted.

Derivative:
moonless adj.

Etymology:
OE mona f. Gmc, rel. to MONTH

N  period, age, era, second, minute, hour, day, week, month, quarter, year, decade, decenniumm lustrum, quinquennium, lifetime, generation, epoch, ghurry, lunation, moon, century, millennium, annus magnus, horary, hourly, annual.

N  changeableness, mutability, inconstancy, versatility, mobility, instability, unstable equilibrium, vacillation, fluctuation, vicissitude, alternation, restlessness, fidgets, disquiet, disquietude, inquietude, unrest, agitation, moon, Proteus, chameleon, quicksilver, shifting sands, weathercock, harlequin, Cynthia of the minute, April showers, wheel of Fortune, transientness, changeable, changeful, changing, mutable, variable, checkered, ever changing, protean, proteiform, versatile, unstaid, inconstant, unsteady, unstable, unfixed, unsettled, fluctuating, restless, agitated, erratic, fickle, irresolute, capricious, touch and go, inconsonant, fitful, spasmodic, vibratory, vagrant, wayward, desultory, afloat, alternating, alterable, plastic, mobile, transient, wavering, seesaw, off and on, a rolling stone gathers no moss, pictra mossa non fa muschis, honores mutant mores, varium et mutabile semper femina.

N  world, creation, nature, universe, earth, globe, wide world, cosmos, kosmos, terraqueous globe, sphere, macrocosm, megacosm, music of the spheres, heavens, sky, welkin, empyrean, starry cope, starry heaven, starry host, firmament, Midgard, supersensible regions, varuna, vault of heaven, canopy of heaven, celestial spaces, heavenly bodies, stars, asteroids, nebulae, galaxy, milky way, galactic circle, via lactea, ame no kawa, sun, orb of day, Apollo, Phoebus, photosphere, chromosphere, solar system, planet, planetoid, comet, satellite, moon, orb of night, Diana, silver-footed queen, aerolite, meteor, planetary ring, falling star, shooting star, meteorite, uranolite, constellation, zodiac, signs of the zodiac, Charles's wain, Big Dipper, Little Dipper, Great Bear, Southern Cross, Orion's belt, Cassiopea's chair, Pleiades, colures, equator, ecliptic, orbit, astronomy, uranography, uranology, cosmology, cosmography, cosmogony, eidouranion, orrery, geodesy, star gazing, star gazer, astronomer, observatory, planetarium, cosmic, cosmical, mundane, terrestrial, terrestrious, terraqueous, terrene, terreous, telluric, earthly, geotic, under the sun, sublunary, subastral, solar, heliacal, lunar, celestial, heavenly, sphery, starry, stellar, sidereal, sideral, astral, nebular, uranic, in all creation, on the face of the globe, here below, under the sun, die Weltgeschichte ist das Weltergesicht, earth is but the frozen echo of the silent voice o, green calm below, blue quietness above, hanging in a golden chain this pendant World, nothing in nature is unbeautiful, silently as a dream the fabric rose, some touch of nature's genial glow, this majestical roof fretted with golden fire, through knowledge we behold the World's creation.

blue moon, full moon, full moon maple, full phase of the moon, half moon, harvest moon, moon about, moon around, moon blindness, moon carrot, moon curser, moon daisy, moon on, moon ray, moon shaped, moon shell, moon shot, moon struck, moon trefoil, new moon, new phase of the moon, phase of the moon, sun myung moon