The Collaborative International Dictionary of English v.0.48:

Luminary \Lu"mi*na*ry\, n.; pl. Luminaries, [F. luminaire, L.
   luminare a light or lamp, which was lighted in the churches,
   a luminary, fr. lumen, luminis, light, fr. lucere to be
   light, to shine, lux, lucis, light. See Light.]
   [1913 Webster]
   1. Any body that gives light, especially one of the heavenly
      bodies. " Radiant luminary." --Skelton.
      [1913 Webster]

            Where the great luminary . . .
            Dispenses light from far.             --Milton.
      [1913 Webster]

   2. One who illustrates any subject, or enlightens mankind;
      as, Newton was a distinguished luminary.
      [1913 Webster]

WordNet (r) 3.0 (2006):

luminary
    n 1: a celebrity who is an inspiration to others; "he was host
         to a large gathering of luminaries" [syn: luminary,
         leading light, guiding light, notable, notability]

Moby Thesaurus II by Grady Ward, 1.0:

83 Moby Thesaurus words for "luminary":
   VIP, actinic, big, big name, big-timer, candle, catoptric,
   celebrity, chief, constellation, cynosure, electric light bulb,
   electronics king, eminence, figure, fire, first-rater, flame,
   folk hero, galaxy, genius, glim, great man, heliographic,
   heliological, hero, heroine, honcho, idol, illuminant, illuminator,
   immortal, important person, incandescent body, king, lamp, lantern,
   lead, leader, leading light, light, light bulb, light source, lion,
   luminal, luminant, luminaries, man of mark, master spirit, match,
   moon, nabob, name, notability, notable, paramount, person of note,
   personage, photic, photoactinic, photologic, pleiad, pop hero,
   popular hero, popular idol, prima donna, principal, prodigy,
   public figure, social lion, somebody, source of light, star, stars,
   sun, superstar, taper, top dog, topnotcher, torch, virtuoso,
   wonder, worthy



The Devil's Dictionary (1881-1906):

LUMINARY, n.  One who throws light upon a subject; as an editor by not
writing about it.