The Collaborative International Dictionary of English v.0.48:

Solar \So"lar\, n. [OE. soler, AS. solere, L. solarium, from sol
   the sun. See Solar, a.]
   A loft or upper chamber; a garret room. [Obs.] [Written also
   soler, solere, sollar.] --Oxf. Gloss.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Solar \So"lar\, a. [L. solaris, fr. sol the sun; akin to As.
   s[=o]l, Icel. s[=o]l, Goth. sauil, Lith. saule, W. haul,.
   sul, Skr. svar, perhaps to E. sun:F. solaire. Cf. Parasol.
   Sun.]
   1. Of or pertaining to the sun; proceeding from the sun; as,
      the solar system; solar light; solar rays; solar
      influence. See Solar system, below.
      [1913 Webster]

   2. (Astrol.) Born under the predominant influence of the sun.
      [Obs.]
      [1913 Webster]

            And proud beside, as solar people are. --Dryden.
      [1913 Webster]

   3. Measured by the progress or revolution of the sun in the
      ecliptic; as, the solar year.
      [1913 Webster]

   4. Produced by the action of the sun, or peculiarly affected
      by its influence.
      [1913 Webster]

            They denominate some herbs solar, and some lunar.
                                                  --Bacon.
      [1913 Webster]

   Solar cycle. See under Cycle.

   Solar day. See Day, 2.

   Solar engine, an engine in which the energy of solar heat
      is used to produce motion, as in evaporating water for a
      steam engine, or expanding air for an air engine.

   Solar flowers (Bot.), flowers which open and shut daily at
      certain hours.

   Solar lamp, an argand lamp.

   Solar microscope, a microscope consisting essentially,
      first, of a mirror for reflecting a beam of sunlight
      through the tube, which sometimes is fixed in a window
      shutter; secondly, of a condenser, or large lens, for
      converging the beam upon the object; and, thirdly, of a
      small lens, or magnifier, for throwing an enlarged image
      of the object at its focus upon a screen in a dark room or
      in a darkened box.
      [1913 Webster]
      [1913 Webster]

   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.
      [1913 Webster]

   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:
         [1913 Webster] I. -- Major Planets. Symbol.Name.Mean
         distance -- that of the Earth being unity.Period in
         days.Eccentricity.Inclination of orbit.Diameter in
         miles ?????????????????????
         [1913 Webster] 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 ?????????????????????
         [1913 Webster]

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

   Solar time. See Apparent time, under Time.
      [1913 Webster]

WordNet (r) 3.0 (2006):

solar
    adj 1: relating to or derived from the sun or utilizing the
           energies of the sun; "solar eclipse"; "solar energy"

Moby Thesaurus II by Grady Ward, 1.0:

48 Moby Thesaurus words for "solar":
   Cynthian, anagalactic, asteroidal, astral, astrologic,
   astrologistic, astrologous, astronomic, astrophysical, celestial,
   circumplanetary, cislunar, empyreal, empyrean, equinoctial,
   extragalactic, galactic, heavenly, heliacal, intercosmic,
   interplanetary, intersidereal, interstellar, lunar, lunary, lunate,
   lunular, lunulate, meteoric, meteoritic, nebular, nebulose,
   nebulous, planetal, planetarian, planetary, planetesimal,
   semilunar, sidereal, sphery, star-spangled, star-studded, starry,
   stellar, stellary, terrestrial, uranic, zodiacal