mach
n. uncountablen. a measurement of speed that compares how fast an object is moving to the speed of sound. If a plane is flying at Mach 1, it is traveling at the speed of sound.
n. a dimensionless unit representing the ratio of the speed of an object to the local speed of sound. Typically used in aviation and fluid dynamics to describe supersonic or subsonic velocities.
The jet reached Mach 2 during the test flight.
Pilots must monitor their instruments closely as the aircraft approaches Mach 1 to manage the effects of the sound barrier.
Engineers designed the experimental craft to withstand the extreme thermal stresses generated when flying at speeds exceeding Mach 5 in the upper atmosphere.
* As a Polish, Czech, Slovak, Ukrainian, and Lower Sorbian surname, from pet forms produced by truncation of personal names beginning with Ma- such as Matej, Martin, or Maciej, and the addition of the Slavic suffix -ch. * As a Jewish surname, from German Mache (“work”). * Less commonly, a respelling of Hungarian Mács, a pet form of names corresponding to Matthew. * In some cases, from Vietnamese (Mạch, itself from the Chinese name 麥 /麦) or Cambodian, from Khmer ម៉ាច (maac).
Usually followed by a number (e.g., 'Mach 1') and functions as a title or proper name in that context; does not take an article when used with a specific value.
The plane flew at 2 Machs.The plane flew at Mach 2.Mach is used as a unit prefix followed by a number, rather than a pluralized noun following a number.