Definition of "tracer bullet" []

• A bullet that leaves a luminous or smoky trail. (noun)

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

• "This guard must have seen the first go under, perhaps seen where all the bubbles the first one brought in coagulated, because suddenly there was a terrible noise inside Janus’s head, inside it, all around it, and from the center of the bubble mass he saw a streak of bubbles fly through the ice as fast as a tracer bullet in wartime night."