Definition of "ultrasonic" []

• Of or relating to acoustic frequencies above the range audible to the human ear, or above approximately 20,000 hertz. (adjective)
• Of, relating to, or involving ultrasound. (adjective)

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.

• "Mexican Freetail bats sing mostly in ultrasonic frequencies that are right above the upper limit of human hearing."
• "It also has the world’s smallest and lightest gyro-sensor and dynamic lift comes from powerful ultra-thin ultrasonic motors and newly designed, optimally shaped main rotors."
• "I (unintelligible) to the factory and they used a technique called ultrasonic welding to glue plastic components together."