crois·sant (krwä-säN ', kre-sänt ')

n. A rich, crescent-shaped roll of leavened dough or puff pastry.
[French, from Old French creissant, croissant, crescent; see crescent.]

Word History: The words croissant and crescent illustrate double borrowings, each coming into English from a different form of the same French word. In Latin the word crescere, "to grow," when applied to the moon meant "to wax," as in the phrase luna crescens, "waxing moon." [...]

Croissant is not an English development but rather a borrowing of the Modern French descendant of Old French croissant. It is first recorded in English in 1899. French croissant was used to translate German Hörnchen, the name given by the Viennese to this pastry, which was first baked in 1689 to commemorate the raising of the siege of Vienna by the Turks, whose symbol was the crescent.

? The American Heritage Dictionary of the English Language