Definition of Mach in English:


(also Mach number)

Pronunciation: /mɑːk//mak/


  • The ratio of the speed of a body to the speed of sound in the surrounding medium. It is often used with a numeral (as Mach 1, Mach 2, etc.) to indicate the speed of sound, twice the speed of sound, etc.

    • ‘They are boost launched from a zero length launcher and then powered by a jet engine in the cruise, reaching speeds up to 0.53 Mach.’
    • ‘The 186-pound AIM - 9 has been produced in many variants, but may be described in general as a solid fuel rocket with a Mach 2 speed and a range of 10 miles.’
    • ‘Cleet and his brethren have a Mach 2 - nearly 1,400 mph - passport out of harm's way.’
    • ‘It will also travel at speeds similar to today's fastest wide bodies, Mach 0.85.’
    • ‘On its third flight, the aircraft broke the sound barrier, reaching a speed of Mach 1.1.’
    • ‘She must hold a perfectly aerodynamic headfirst position with her arms at her sides when she hits Mach 1 (the speed of sound) and goes through the shock wave.’
    • ‘A Mach number is a measure of airspeed, and not of ground speed.’
    • ‘The missile uses command updated inertial guidance and reaches high subsonic speed, 0.9 Mach.’
    • ‘Sidewinder is an all-aspect short-range missile with maximum speed over Mach 2, for defence against hostile aircraft.’
    • ‘Eurofighter has ‘supercruise’ capability: it can fly at sustained speeds of over Mach 1 without the use of afterburner.’
    • ‘The A - 10 can also carry the Sidewinder air-to-air missile, which is an all-aspect short-range missile with maximum speed over Mach 2.’
    • ‘The engine develops 131.7kN and the speed of the aircraft is Mach 2.’
    • ‘Max cruise speed remains the same for both airplanes at Mach 0.82.’
    • ‘Want to make a Mach 5 airplane, bridge the Bering Strait, shrink a chip by a factor of ten?’
    • ‘When the P - 38 wing developed a supersonic enclosure at the critical Mach number, the center of pressure moved aft, causing the nose to tuck down.’
    • ‘From Tiger Moths, to the Mach 1.2 Albatross jet, the business flies the aircraft that stir the blood.’
    • ‘To prepare for the Mach 10 flight, the third scramjet was upgraded slightly.’
    • ‘The use of Mach number to characterize flight speed is rooted in the basic physics of fluid flow.’
    • ‘The party atmosphere as we roared across the Atlantic at twice the speed of sound, Mach 2, 1,350 miles per hour, at the very edge of space.’
    • ‘Going Mach 2 in the sleek jet ranked in the Top 10 among viewers.’


1930s: named after Ernst Mach(see Mach, Ernst).