The Collaborative International Dictionary of English v.0.48:

Moon \Moon\ (m[=oo]n), n. [OE. mone, AS. m[=o]na; akin to D.
   maan, OS. & OHG. m[=a]no, G. mond, Icel. m[=a]ni, Dan. maane,
   Sw. m[*a]ne, Goth. m[=e]na, Lith. men[*u], L. mensis month,
   Gr. mh`nh moon, mh`n month, Skr. m[=a]s moon, month; prob.
   from a root meaning to measure (cf. Skr. m[=a] to measure),
   from its serving to measure the time. [root]271. Cf. Mete
   to measure, Menses, Monday, Month.]
   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. --Cowper.
      [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; as, it's been many moons since I last
      visited Washington. --Shak.
      [1913 Webster]

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

   5. The deliberately exposed naked buttocks. [slang]
      [PJC]

   Moon blindness.
      (a) (Far.) A kind of ophthalmia liable to recur at
          intervals of three or four weeks.
      (b) (Med.) Hemeralopia.

   Moon dial, a dial used to indicate time by moonlight.

   Moon face, a round face like a full moon.

   Moon madness, lunacy. [Poetic]

   Moon month, a lunar month.

   Moon trefoil (Bot.), a shrubby species of medic (Medicago
      arborea). See Medic.

   Moon year, a lunar year, consisting of lunar months, being
      sometimes twelve and sometimes thirteen.

   blue moon, see blue moon in the vocabulary.

   many moons, a long time.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Moon \Moon\, v. t. [imp. & p. p. Mooned; p. pr. & vb. n.
   Mooning.]
   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.                    --Holland.
      [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]

The Collaborative International Dictionary of English v.0.48:

Moon \Moon\, v. i.
   To act if moonstruck; to wander or gaze about in an
   abstracted manner.
   [1913 Webster]

         Elsley was mooning down the river by himself. --C.
                                                  Kingsley.
   [1913 Webster]

WordNet (r) 3.0 (2006):

Moon
    n 1: the natural satellite of the Earth; "the average distance
         to the Moon is 384,400 kilometers"; "men first stepped on
         the moon in 1969" [syn: Moon, moon]
    2: any object resembling a moon; "he made a moon lamp that he
       used as a night light"; "the clock had a moon that showed
       various phases"
    3: the period between successive new moons (29.531 days) [syn:
       lunar month, moon, lunation, synodic month]
    4: the light of the Moon; "moonlight is the smuggler's enemy";
       "the Moon was bright enough to read by" [syn: moonlight,
       moonshine, Moon]
    5: United States religious leader (born in Korea) who founded
       the Unification Church in 1954; was found guilty of
       conspiracy to evade taxes (born in 1920) [syn: Moon, Sun
       Myung Moon]
    6: any natural satellite of a planet; "Jupiter has sixteen
       moons"
    v 1: have dreamlike musings or fantasies while awake; "She
         looked out the window, daydreaming" [syn: daydream,
         moon]
    2: be idle in a listless or dreamy way [syn: moon, moon
       around, moon on]
    3: expose one's buttocks to; "moon the audience"

Moby Thesaurus II by Grady Ward, 1.0:

144 Moby Thesaurus words for "moon":
   April showers, Artemis, Ashtoreth, Astarte, Cynthia, Diana, Hecate,
   Hekate, Luna, Phoebe, Proteus, Selene, abundant year,
   academic year, annum, artificial satellite, be absent,
   bissextile year, bum around, calendar month, calendar year, candle,
   century, chameleon, cloud shapes, common year, crescent,
   crescent moon, day, daydream, decade, decennary, decennium,
   decrescent, decrescent moon, defective year, demilune, divagate,
   do nothing, dream, electric light bulb, fantasy, fire, fiscal year,
   flame, fortnight, full moon, gibbous moon, glim, go woolgathering,
   goof off, half-moon, hang around, harvest moon, hour, idle,
   illuminant, illuminator, incandescent body, increscent,
   increscent moon, kaleidoscope, lamp, lantern, laze, lazy,
   leap year, lie around, light, light bulb, light source, loaf,
   loiter about, loll around, lollop around, lounge, lounge around,
   luminant, luminary, lunar month, lunar year, lunation, luster,
   lustrum, man-hour, match, mercury, microsecond, millennium,
   millisecond, minute, moment, month, mooch around, moon around,
   muse, new moon, orb of night, pipe-dream, quarter, queen of heaven,
   queen of night, quicksilver, quinquennium, regular year,
   rolling stone, satellite, second, semester, session,
   shifting sands, sidereal year, silvery moon, sit around, slouch,
   slouch around, solar year, source of light, stand around, stargaze,
   stars, stray, sun, taper, term, the wandering Moon, the weather,
   torch, trimester, twelvemonth, wander, waning crescent moon,
   waning moon, water, waxing crescent moon, waxing moon,
   weather vane, weathercock, week, weekday, wet moon,
   wheel of fortune, whirligig, year



Easton's 1897 Bible Dictionary:

Moon
   heb. yareah, from its paleness (Ezra 6:15), and lebanah, the
   "white" (Cant. 6:10; Isa. 24:23), was appointed by the Creator
   to be with the sun "for signs, and for seasons, and for days,
   and years" (Gen. 1:14-16). A lunation was among the Jews the
   period of a month, and several of their festivals were held on
   the day of the new moon. It is frequently referred to along with
   the sun (Josh. 10:12; Ps. 72:5, 7, 17; 89:36, 37; Eccl. 12:2;
   Isa. 24:23, etc.), and also by itself (Ps. 8:3; 121:6).

     The great brilliance of the moon in Eastern countries led to
   its being early an object of idolatrous worship (Deut. 4:19;
   17:3; Job 31:26), a form of idolatry against which the Jews were
   warned (Deut. 4:19; 17:3). They, however, fell into this
   idolatry, and offered incense (2 Kings 23:5; Jer. 8:2), and also
   cakes of honey, to the moon (Jer. 7:18; 44:17-19, 25).