The Collaborative International Dictionary of English v.0.48:

ecliptic \e*clip"tic\ ([-e]*kl[i^]p"t[i^]k), n. [Cf. F.
   ['e]cliptique, L. linea ecliptica, Gr. 'ekleiptiko`s, prop.
   adj., of an eclipse, because in this circle eclipses of the
   sun and moon take place. See Ecliptic, a.]
   1. (Astron.) A great circle of the celestial sphere, making
      an angle with the equinoctial of about 23[deg] 28'. It is
      the apparent path of the sun, or the real path of the
      earth as seen from the sun.
      [1913 Webster]

   2. (Geog.) A great circle drawn on a terrestrial globe,
      making an angle of 23[deg] 28' with the equator; -- used
      for illustrating and solving astronomical problems.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Ecliptic \E*clip"tic\, a. [L. eclipticus belonging to an
   eclipse, Gr. 'ekleiptiko`s. See Eclipse.]
   1. Pertaining to the ecliptic; as, the ecliptic way.
      [1913 Webster]

   2. Pertaining to an eclipse or to eclipses.
      [1913 Webster]

   Lunar ecliptic limit (Astron.), the space of 12[deg] on the
      moon's orbit from the node, within which, if the moon
      happens to be at full, it will be eclipsed.

   Solar ecliptic limit, the space of 17[deg] from the lunar
      node, within which, if a conjunction of the sun and moon
      occur, the sun will be eclipsed.
      [1913 Webster]

WordNet (r) 3.0 (2006):

ecliptic
    n 1: the great circle representing the apparent annual path of
         the sun; the plane of the Earth's orbit around the sun;
         makes an angle of about 23 degrees with the equator; "all
         of the planets rotate the sun in approximately the same
         ecliptic"

Moby Thesaurus II by Grady Ward, 1.0:

55 Moby Thesaurus words for "ecliptic":
   anklet, aphelion, apogee, armlet, astronomical longitude,
   autumnal equinox, band, belt, bracelet, celestial equator,
   celestial longitude, celestial meridian, cincture, cingulum,
   circle, collar, collarband, colures, earring, equator, equinoctial,
   equinoctial circle, equinoctial colure, equinox, fascia, fillet,
   finger ring, galactic longitude, geocentric longitude,
   geodetic longitude, girdle, girt, girth, great circle,
   heliocentric longitude, hoop, longitude, meridian, neckband,
   necklace, nose ring, orbit, perigee, perihelion, period, quoit,
   ring, small circle, solstitial colure, trajectory, vernal equinox,
   wristband, wristlet, zodiac, zone