The Collaborative International Dictionary of English v.0.48:

'Eclair \['E]`clair"\, n. [F.] (Cookery)
   A kind of frosted cake, containing flavored cream.
   [1913 Webster]

WordNet (r) 3.0 (2006):

eclair
    n 1: oblong cream puff

Moby Thesaurus II by Grady Ward, 1.0:

24 Moby Thesaurus words for "eclair":
   Danish pastry, French pastry, baklava, blintz, chocolate eclair,
   cream puff, dowdy, pandowdy, pastry, pasty, patisserie, patty,
   patty-shell, pie, puff, quiche, rosette, strudel, tart, timbale,
   tipsy cake, trifle, turnover, vol-au-vent