What does transonic mean?
Transonic is an adjective describing motion at or near the speed of sound. In aeronautics, it is especially associated with the narrow speed band around Mach 1, where airflow over an aircraft changes character and pressure waves may become prominent. The term is technical and formal rather than conversational, but it is useful because it marks a transition, not simply one exact speed. A transonic aircraft is approaching, crossing, or just passing the speed of sound; a supersonic vehicle is already flying faster than sound. Transonic flight can involve shock waves, buffeting, and demands on airframe design. The word is therefore especially meaningful in aviation and aerospace, while also applying more broadly to speeds around the speed of sound in a given medium. It conveys both a threshold and a range, making it more precise than merely calling such motion fast.
adjectiveRelating to speeds at or near the speed of sound, especially in aeronautics; describing the conditions encountered as a vehicle approaches or crosses Mach 1.
- Relating to or occurring at speeds at or near the speed of sound, especially during flight through the transonic speed range around Mach 1.
"The aircraft encountered severe buffeting as it entered the transonic regime."
"The test aircraft experienced turbulence and buffeting while in transonic flight."
"Engineers studied the transonic behaviour of the wing before approving the new design."
Transonic marks the high-stakes threshold where flight crosses the speed of sound.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does transonic come from?
Transonic was formed in 20th-century English from trans-, meaning “across” or “beyond,” and sonic, meaning “relating to sound.” Sonic is borrowed from Latin sonicus, which was derived from sonus, meaning “sound.” The combination reflects the idea of crossing into or passing through the sound barrier.
Related word forms
How transonic is actually used
A technical and formal term used chiefly in aviation, aeronautics, and aerospace engineering; it is uncommon in general conversation.
Easily confused with transonic
Transonic refers broadly to speeds at or near Mach 1, whereas supersonic specifically means faster than the speed of sound.