The Collaborative International Dictionary of English v.0.48:

Lunar \Lu"nar\ (l[=u]"n[~e]r), a. [L. lunaris, fr. luna the
   moon. See Luna, and cf. Lunary.]
   1. Of or pertaining to the moon; as, lunar observations.
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   2. Resembling the moon; orbed. --Dryden.
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   3. Measured by the revolutions of the moon; as, a lunar
      month.
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   4. Influenced by the moon, as in growth, character, or
      properties; as, lunar herbs. --Bacon.
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   Lunar caustic (Med. Chem.), silver nitrate prepared to be
      used as a cautery; -- so named because silver was called
      luna by the ancient alchemists.

   Lunar cycle. Same as Metonic cycle. See under Cycle.

   Lunar distance, the angular distance of the moon from the
      sun, a star, or a planet, employed for determining
      longitude by the lunar method.

   Lunar method, the method of finding a ship's longitude by
      comparing the local time of taking (by means of a sextant
      or circle) a given lunar distance, with the Greenwich time
      corresponding to the same distance as ascertained from a
      nautical almanac, the difference of these times being the
      longitude.

   Lunar month. See Month.

   Lunar observation, an observation of a lunar distance by
      means of a sextant or circle, with the altitudes of the
      bodies, and the time, for the purpose of computing the
      longitude.

   Lunar tables.
      (a) (Astron.) Tables of the moon's motions, arranged for
          computing the moon's true place at any time past or
          future.
      (b) (Navigation) Tables for correcting an observed lunar
          distance on account of refraction and parallax.

   Lunar year, the period of twelve lunar months, or 354 days,
      8 hours, 48 minutes, and 34.38 seconds.
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The Collaborative International Dictionary of English v.0.48:

Month \Month\ (m[u^]nth), n. [OE. month, moneth, AS.
   m[=o]n[eth], m[=o]na[eth]; akin to m[=o]na moon, and to D.
   maand month, G. monat, OHG. m[=a]n[=o]d, Icel. m[=a]nu[eth]r,
   m[=a]na[eth]r, Goth. m[=e]n[=o][thorn]s. [root]272. See
   Moon.]
   One of the twelve portions into which the year is divided;
   the twelfth part of a year, corresponding nearly to the
   length of a synodic revolution of the moon, -- whence the
   name. In popular use, a period of four weeks is often called
   a month.
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   Note: In the common law, a month is a lunar month, or
         twenty-eight days, unless otherwise expressed.
         --Blackstone. In the United States the rule of the
         common law is generally changed, and a month is
         declared to mean a calendar month. --Cooley's
         Blackstone.
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   A month mind.
   (a) A strong or abnormal desire. [Obs.] --Shak.
   (b) A celebration made in remembrance of a deceased person a
       month after death. --Strype.

   Calendar months, the months as adjusted in the common or
      Gregorian calendar; April, June, September, and November,
      containing 30 days, and the rest 31, except February,
      which, in common years, has 28, and in leap years 29.

   Lunar month, the period of one revolution of the moon,
      particularly a synodical revolution; but several kinds are
      distinguished, as the synodical month, or period from
      one new moon to the next, in mean length 29 d. 12 h. 44 m.
      2.87 s.; the nodical month, or time of revolution from
      one node to the same again, in length 27 d. 5 h. 5 m. 36
      s.; the sidereal, or time of revolution from a star to
      the same again, equal to 27 d. 7 h. 43 m. 11.5 s.; the
      anomalistic, or time of revolution from perigee to
      perigee again, in length 27 d. 13 h. 18 m. 37.4 s.; and
      the tropical, or time of passing from any point of the
      ecliptic to the same again, equal to 27 d. 7 h. 43 m. 4.7
      s.

   Solar month, the time in which the sun passes through one
      sign of the zodiac, in mean length 30 d. 10 h. 29 m. 4.1
      s.
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WordNet (r) 3.0 (2006):

lunar month
    n 1: the period between successive new moons (29.531 days) [syn:
         lunar month, moon, lunation, synodic month]