The Collaborative International Dictionary of English v.0.48:

Eclat \E*clat"\, n. [F. ['e]clat a fragment, splinter,
   explosion, brilliancy, splendor, fr. ['e]clater to splinter,
   burst, explode, shine brilliantly, prob. of German origin;
   cf. OHG. sleizan to slit, split, fr. sl[imac]zan, G.
   schleissen; akin to E. slit.]
   1. Brilliancy of success or effort; splendor; brilliant show;
      striking effect; glory; renown. "The eclat of Homer's
      battles." --Pope.
      [1913 Webster]

   2. Demonstration of admiration and approbation; applause.
      --Prescott.
      [1913 Webster]

WordNet (r) 3.0 (2006):

eclat
    n 1: enthusiastic approval; "the book met with modest acclaim";
         "he acknowledged the plaudits of the crowd"; "they gave him
         more eclat than he really deserved" [syn: acclaim,
         acclamation, plaudits, plaudit, eclat]
    2: ceremonial elegance and splendor; "entered with much eclat in
       a coach drawn by eight white horses" [syn: pomp, eclat]
    3: brilliant or conspicuous success or effect; "the eclat of a
       great achievement"

Moby Thesaurus II by Grady Ward, 1.0:

100 Moby Thesaurus words for "eclat":
   PR, acclaim, acclamation, applause, ballyhoo, bang, big hand,
   blazon, blurb, bravura, bright light, brilliance, brilliancy,
   burst of applause, celebrity, character, cheer, clap, clapping,
   clapping of hands, common knowledge, cry, currency, daring, dash,
   daylight, demonstration, display, distinction, dramatics, encore,
   etalage, exhibition, exhibitionism, exposure, false front, fame,
   famousness, fanfaronade, figure, flair, flaunt, flaunting,
   flourish, glare, glory, hand, handclap, handclapping, histrionics,
   hoopla, hue and cry, kudos, limelight, luster, manifestation,
   maximum dissemination, name, notoriety, notoriousness, ovation,
   pageant, pageantry, parade, plaudit, plug, popularity,
   press notice, prominence, public eye, public knowledge,
   public relations, public report, publicity, publicity story,
   publicness, puff, reclame, recognition, remarkableness, renown,
   report, reputation, repute, round of applause, sham, show,
   showing-off, spectacle, splash, splurge, spotlight, staginess,
   standing, the bubble reputation, theatrics, thunder of applause,
   vaunt, vogue, write-up