subsonic

American  

[suhb-son-ik] / sʌbˈsɒn ɪk /

adjective

1. noting or pertaining to a speed less than that of sound in air at the same height above sea level.

2. infrasonic.

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subsonic British  

/ sʌbˈsɒnɪk /

adjective

1. being, having, or travelling at a velocity below that of sound

   a subsonic aircraft

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subsonic Scientific  

/ sŭb-sŏn′ĭk /

1. Having a speed less than that of sound in a designated medium, usually air; having a velocity less than Mach 1.

2. Compare hypersonic supersonic transonic

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Other Word Forms

• subsonically adverb

Etymology

Origin of subsonic

1940–45; sub- + sonic ( def. )

Compare meaning

How does subsonic compare to similar and commonly confused words? Explore the most common comparisons:

• subsonic vs. supersonic

Example Sentences

The Burevestnik, which flew at well below the speed of sound, made its debut just as subsonic missiles are increasingly being shot down in Ukraine because modern defensive systems can lock onto them.

From The Wall Street Journal

Even then Tomahawks, which fly at subsonic speeds at a low altitude, could be vulnerable to Russian air defenses.

From The Wall Street Journal

Right above the shores of Huntington Beach, a retired American subsonic T-33 fighter jet darted across the blue canvas of a clear afternoon sky, leaving a spiraling plume of smoke in its wake.

From Los Angeles Times

In terms of purely destructive power, however, hypersonic missiles are not hugely different from supersonic or subsonic cruise missiles, according to Mr Freer.

From BBC

The house was littered with casings from subsonic ammunition of the same brand recovered from the motel room, Avila said.

From Los Angeles Times