sub·​son·​ic | \ ˌsəb-ˈsä-nik How to pronounce subsonic (audio) \

Definition of subsonic

1 : of, relating to, or being a speed less than that of sound in air
2 : moving, capable of moving, or utilizing air currents moving at a subsonic speed

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Other Words from subsonic

subsonically \ ˌsəb-​ˈsä-​ni-​k(ə-​)lē How to pronounce subsonically (audio) \ adverb

Examples of subsonic in a Sentence

Recent Examples on the Web These airplanes are expected to seat 65 to 88 passengers and will travel at subsonic speeds over land and supersonic speeds over water—more than twice as fast as current commercial aircraft. Eric Berger, Ars Technica, "Meet the XB-1: A prototype for a modern supersonic passenger jet," 7 Oct. 2020 In the same way, the air conditioning system has to heat the interior at subsonic speeds and then cool it after Mach 1 is passed. J. A. Maxtone Graham, Popular Mechanics, "You, Too, Can Break the Sound Barrier," 24 Sep. 2020 Yes, the supersonic and subsonic air drag forces can be quite different—this is just one of the things that makes fluid dynamics so complicated. Rhett Allain, Wired, "The Cool Physics of a Supersonic Baseball," 23 Sep. 2020 Entering the atmosphere, the capsule would use its heat shield to absorb the reentry heating and then employ atmospheric drag to slow down to subsonic speeds. Robert Zubrin, National Review, "Might We Find Life on Venus?," 19 Sep. 2020 But projects like these take years, so members of the public—and government leaders—should expect to fly at traditional, subsonic speeds for the foreseeable future. Rob Verger, Popular Science, "Air Force transport jets for VIPs could have a supersonic future," 10 Sep. 2020 This generates enough thrust to drive an aircraft at subsonic speeds. Kyle Mizokami, Popular Mechanics, "The Engine That Will Make Air Force One Hypersonic," 7 Aug. 2020 Skyborg will be available with both subsonic and supersonic engines, indicating both attack and fighter jet versions. Kyle Mizokami, Popular Mechanics, "The F-16's Replacement Won’t Have a Pilot at All," 9 July 2020 Offerings include loads for the 9mm, .40 S&W, and .45 Auto, but maybe more exciting for hunters are the subsonic loads for the .30-30 Winchester, .450 Bushmaster, and even .45-70 Government. Richard Mann, Field & Stream, "Best New Hunting, Long-Range, and Handgun Ammo of the 2020 SHOT Show," 22 Jan. 2020

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'subsonic.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of subsonic

1920, in the meaning defined at sense 3

History and Etymology for subsonic

International Scientific Vocabulary

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Time Traveler for subsonic

Time Traveler

The first known use of subsonic was in 1920

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Statistics for subsonic

Last Updated

16 Oct 2020

Cite this Entry

“Subsonic.” Dictionary, Merriam-Webster, Accessed 26 Oct. 2020.

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More Definitions for subsonic


How to pronounce subsonic (audio)

English Language Learners Definition of subsonic

: slower than the speed of sound

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