Source : Webster's Revised Unabridged Dictionary (1913)

Candlebomb \Can"dle*bomb`\, n.
   1. A small glass bubble, filled with water, which, if placed
      in the flame of a candle, bursts by expansion of steam.

   2. A pasteboard shell used in signaling. It is filled with a
      composition which makes a brilliant light when it
      explodes. --Farrow.