What does hypersonic mean?
Hypersonic is an adjective describing speeds far beyond the speed of sound, conventionally Mach 5 or higher. It is used in aeronautics, spaceflight, defence, and high-speed engineering to describe vehicles, travel, flight, and the physical conditions associated with such motion. At these speeds, air compresses intensely around a vehicle, producing severe heating and powerful aerodynamic forces. The word is also used more loosely in media and technology to emphasize extraordinary speed. In technical contexts, it is more specific than supersonic: the latter means only faster than sound, while hypersonic implies a substantially greater speed. The term is consequently associated with experimental aircraft, reentry vehicles, missiles, and proposed future transportation systems.
adjectiveDenoting or travelling at speeds far greater than the speed of sound, especially at speeds of about Mach 5 or higher. The term is also used for vehicles, aircraft, and technologies designed to operate at such speeds.
- Relating to or travelling at speeds far greater than the speed of sound, especially Mach 5 or higher.
"The aircraft entered hypersonic flight during the test, travelling at several times the speed of sound."
"The test vehicle reached hypersonic speeds shortly after launch."
"Scientists are studying the heating and aerodynamic forces experienced during hypersonic flight."
Hypersonic is where flight stops merely outrunning sound and enters speeds fast enough to generate extraordinary aerodynamic effects.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does hypersonic come from?
The word combines the Greek-derived prefix hypo-, meaning “under” or “below,” with sonic, from Latin sonus, meaning “sound.” Its formation reflects the historical idea of speeds beyond the supersonic range, where the effects of motion through the atmosphere become especially significant. The element sonic also links it to related words such as sonorous, resonance, and consonant, all ultimately connected with Latin sonus.
Related word forms
How hypersonic is actually used
This is primarily a technical term. In engineering and aeronautics, it generally denotes speeds of Mach 5 or greater, although the precise threshold can vary with context. In general journalism, it may be used more loosely for exceptionally high speed.
Easily confused with hypersonic
Supersonic describes speeds above the speed of sound, while hypersonic conventionally refers to much higher speeds, generally Mach 5 and above.