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

If the data from Flight 11 proves promising, the company's engineers will be able to decide if another subsonic test flight is required before the final assault on the supersonic realm later this year. —New Atlas, 14 Jan. 2025

Although most modern subsonic missiles use jet engines because of their smoother operation, pulse jets remain attractive due to their simplicity and low cost. —Vikram Mittal, Forbes, 13 Jan. 2025

Those advantages also have a downside: ramjets are entirely ineffective at low speeds and are often accompanied by turbojets to handle subsonic flight, where the airspeed isn't enough to feed air-hungry ramjet engines. —New Atlas, 20 Dec. 2024

Another possibility experts suggested: The shooter could have chosen subsonic ammunition to avoid detection. —Christopher Cann, The Courier-Journal, 5 Dec. 2024

Word History

Etymology

International Scientific Vocabulary

First Known Use

1920, in the meaning defined at sense 3

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