Definition of "sonar" [sonar]

• A system using transmitted and reflected underwater sound waves to detect and locate submerged objects or measure the distance to the floor of a body of water. (noun)
• An apparatus, as one in a submarine, using sonar. (noun)
• Echolocation. (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.

• "If your sonar is marking fish at 25 feet, for example, let out about 3.5 colors."
• "Their echolocation sonar is far beyond our military science."
• "It was detected about five years ago with sonar from a surface vessel."