machmeter
/ˈmɑːkmiːtər/
noun
- An instrument in an aircraft that shows the ratio of the aircraft's speed to the speed of sound.
- Modern jets have a digital machmeter that displays the Mach number on the cockpit screen.
- The pilot checked the machmeter as the plane approached the speed of sound.
- When the machmeter read 1.0, the aircraft was flying at Mach 1.