subsonic

adjective

sub·​son·​ic ˌsəb-ˈsä-nik 

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

3

: infrasonic sense 1

subsonically

ˌsəb-ˈsä-ni-k(ə-)lē 

adverb

Examples of subsonic in a Sentence

Recent Examples on the Web

Marketed as a low-cost cruise missile, Crossbow weighs about 750 kilograms (around 1,650 pounds), carries a 300-kilogram (660-pound) modular payload, and can fly more than 800 kilometers (500 miles) at high subsonic speeds. —Kapil Kajal, Interesting Engineering, 9 Sep. 2025

The resultant supersonic ban, which slowed the Concorde to subsonic speeds, negated its edge over conventional jets. —Michael Verdon, Robb Report, 18 Aug. 2025

To date, Russia has only delivered Iran a small number of subsonic Yak-130 jet trainers. —Paul Iddon, Forbes.com, 10 Aug. 2025

Renderings show luxurious seats comparable to the contemporary business class offering on any subsonic plane. —Edward Russell, CNN Money, 5 June 2025

Word History

Etymology

International Scientific Vocabulary

First Known Use

1920, in the meaning defined at sense 3

Rhymes for subsonic

• atonic
• benthonic
• bionic
• bosonic
• bubonic
• canonic
• carbonic
• cyclonic
• demonic
• dystonic
• hadronic
• harmonic

Kids Definition

subsonic

adjective

sub·​son·​ic ˌsəb-ˈsän-ik 

ˈsəb-

1

: of, relating to, or being a speed less than that of sound in air

2

: moving, capable of moving, or using air currents moving at a subsonic speed