Definition of "sonobuoy" []

• A buoy equipped with an acoustic receiver and a radio transmitter that emits radio signals when it detects underwater sounds. (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.

• "But after World War II, the Navy was interested in developing a so-called "sonobuoy" that would use sonar to detect submarines in the water and transmit the information to an airplane above."
• "HOT: in reference to a sonobuoy, holding enemy contact."
• "When a submarine changes its course or speed in relation to a sonobuoy, the event shows up as a change in the frequency of the sound source."