Sentence:  Stowed away in the plane Jack had a signal pistol and several red and green cartridges, but until a search plane appeared the <WSD>flares</WSD> would be useless. 
Meaning of the word marked with <WSD> tags:  A type of pyrotechnic that produces a brilliant light without an explosion, used to attract attention in an emergency, to illuminate an area, or as a decoy.