The Collaborative International Dictionary of English v.0.48:

Bengal \Ben*gal"\, prop. n.
   1. A province in India, giving its name to various stuffs,
      animals, etc.
      [1913 Webster]

   2. A thin stuff, made of silk and hair, originally brought
      from Bengal.
      [1913 Webster]

   3. Striped gingham, originally brought from Bengal; Bengal
      stripes.
      [1913 Webster]

   Bengal light, a firework containing niter, sulphur, and
      antimony, and producing a sustained and vivid colored
      light, used in making signals and in pyrotechnics; --
      called also blue light.

   Bengal stripes, a kind of cotton cloth woven with colored
      stripes. See Bengal, 3.

   Bengal tiger. (Zool.). See Tiger.
      [1913 Webster] Bengalee

WordNet (r) 3.0 (2006):

Bengal light
    n 1: a steady bright blue light; formerly used as a signal but
         now a firework