WordNet (r) 3.0 (2006):

croissant
    n 1: very rich flaky crescent-shaped roll [syn: crescent roll,
         croissant]

Moby Thesaurus II by Grady Ward, 1.0:

25 Moby Thesaurus words for "croissant":
   Danish, Danish pastry, English muffin, Parker House roll,
   Yorkshire pudding, bagel, bialy, bialystoker, bun,
   clover-leaf roll, coffee cake, crescent roll, cross bun, crumpet,
   gem, hard roll, hot cross bun, kaiser roll, muffin, onion roll,
   pinwheel roll, popover, roll, scone, soft roll