The speed of a body that has Mach number more than 1 is

The Mach number is defined as the ratio of an object's true airspeed to the local speed of sound. When the Mach number (M) is exactly 1, the object is traveling at the speed of sound. If the Mach number is less than 1 (M < 1), the speed is classified as subsonic. Conversely, when a body moves at a speed greater than the speed of sound, resulting in a Mach number greater than 1 (M > 1), the speed is classified as supersonic. Supersonic flight regimes typically range from Mach 1 to Mach 5, beyond which the speed is termed hypersonic. While the speed of sound varies with temperature and altitude, the classification of 'supersonic' remains strictly tied to the condition of exceeding Mach 1.

Sources

1. [1] https://www.grc.nasa.gov/www/k-12/airplane/mach.html