The Collaborative International Dictionary of English v.0.48:

Flambeau \Flam"beau\; n.; pl. Flambeauxor Flambeaus. [F.,
   fr. OF. flambe flame, for flamble, from L. flammula a little
   flame, dim. of flamma flame. See Flame.]
   A flaming torch, esp. one made by combining together a number
   of thick wicks invested with a quick-burning substance
   (anciently, perhaps, wax; in modern times, pitch or the
   like); hence, any torch.
   [1913 Webster]

WordNet (r) 3.0 (2006):

flambeau
    n 1: a flaming torch (such as are used in processions at night)