Source : Webster's Revised Unabridged Dictionary (1913)

Month \Month\, n. [OE. month, moneth, AS. m[=o]n?, m[=o]na?;
   akin to m[=o]na moon, and to D. maand month, G. monat, OHG.
   m[=a]n[=o]d, Icel. m[=a]nu?r, m[=a]na?r, Goth. m[=e]n[=o]?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.

   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.

   {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.



   {Solar month}. See under {Month}.

   {Solar oil}, a paraffin oil used an illuminant and lubricant.
      

   {Solar phosphori} (Physics), certain substances, as the
      diamond, siulphide of barium (Bolognese or Bologna
      phosphorus), calcium sulphide, etc., which become
      phosphorescent, and shine in the dark, after exposure to
      sunlight or other intense light.

   {Solar plexus} (Anat.), a nervous plexus situated in the
      dorsal and anterior part of the abdomen, consisting of
      several sympathetic ganglia with connecting and radiating
      nerve fibers; -- so called in allusion to the radiating
      nerve fibers.

   {Solar spots}. See {Sun spots}, under {Sun}.

   {Solar system} (Astron.), the sun, with the group of
      celestial bodies which, held by its attraction, revolve
      round it. The system comprises the major planets, with
      their satellites; the minor planets, or asteroids, and the
      comets; also, the meteorids, the matter that furnishes the
      zodiacal light, and the rings of Saturn. The satellites
      that revolve about the major planets are twenty-two in
      number, of which the Earth has one (see {Moon}.), Mars
      two, Jupiter five, Saturn nine, Uranus four, and Neptune
      one. The asteroids, between Mars and Jupiter, thus far
      discovered (1900), number about five hundred, the first
      four of which were found near the beginning of the
      century, and are called Ceres, Pallas, Juno, and Vesta.

   Note: The principal elements of the major planets, and of the
         comets seen at more than one perihelion passage, are
         exhibited in the following tables: -- I. -- Major
         Planets. Symbol.Name.Mean distance -- that of the Earth
         being unity.Period in days.Eccentricity.Inclination of
         orbit.Diameter in miles ????????????????????? II. --
         Periodic Comets. Name.Greatest distance from sun.Least
         distance from sun.Inclination of orbit.Perihelion
         passage. [deg] [min] 54 Encke's3.314.100.34212 541885.2
         ?????????????????????

   {Solar telegraph}, telegraph for signaling by flashes of
      reflected sunlight.

   {Solar time}. See {Apparent time}, under {Time}.

Source : WordNet®

solar month
     n : one-twelfth of a solar or tropical year