What does speedo mean?
A speedo is an informal word for a speedometer, the instrument that indicates a vehicle's speed. It is especially common in British and Australian English, where speakers use it in everyday conversation as a shortened alternative to the formal word “speedometer.” The expression can refer either to the complete instrument or, in phrases such as “check the speedo,” to its display or dial. “Speedo” is particularly associated with cars and motorcycles, though it can apply to any vehicle fitted with a speed indicator. Its brevity makes it useful in speech, while “speedometer” remains the preferred term in technical manuals, official documents, and other formal contexts. The word is also sometimes used for the displayed speed reading itself, although “speedometer reading” is the less ambiguous expression in careful writing.
nounAn informal, abbreviated name for a speedometer.
- An informal name for a speedometer, especially in British and Australian English.
"The speedo was climbing rapidly as the car gathered speed."
"He glanced at the speedo and eased off the accelerator."
"The old car's speedo fluctuated wildly at high speeds."
The plural takes no additional ending.
"The mechanic checked both speedos before the road trip."
The everyday word “speedometer” has a perfectly serviceable shorter cousin.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does speedo come from?
The word is a clipping of “speedometer.” The longer word was formed from “speed” and the measuring suffix “-ometer,” whose ultimate source is Greek metron, meaning “measure.” The shortened form became established in colloquial British English and later spread into Australian usage.
How speedo is actually used
Informal and conversational; it is especially common in British and Australian English. The full word “speedometer” is preferred in formal and technical writing.
Easily confused with speedo
A speedometer is the full standard term for the instrument, whereas a speedo is an informal clipping.