Definition of "signal light" []

• A fire set as a signal (noun)

WordNet. Princeton University. 2010.

• "The Star Spear quivered the moment the signal light went out, and explosions at the coupling points sent vibrations through the rocket ship."
• "The signal light at the tunnel’s entrance showed red; they waited for the green, Kate thinking of the story’s narrator and his dashboard-denting trip through this same tunnel."
• "At ten, the same night, in mid-river of the Charles, oarsmen two, with passenger silent and grim, had seen the signal light out-swung, and rowed with speed for the Charlestown shore."