noun Etymology: Ernst Mach died 1916 Austrian physicist Date: 1937 a number representing the ratio of the speed of a body (as an aircraft) to the speed of sound in a surrounding medium (as air)
MACH NUMBER
Meaning of MACH NUMBER in English
Merriam Webster. Explanatory English dictionary Merriam Webster. Толковый словарь английского языка Мерриам-Уэбстер. 2012