Word Study
mach
WORDNET DICTIONARY
Noun mach has 1 sense
- mach(n = noun.person) ernst mach - Austrian physicist and philosopher who introduced the Mach number and who founded logical positivism (1838-1916); Array is a kind of philosopher, physicist
OXFORD DICTIONARY
mach, n. (in full Mach number) the ratio of the speed of a body to the speed of sound in the surrounding medium.
Idiom
Mach one (or two etc.) the speed (or twice the speed) of sound.
Etymology
E. Mach, Austrian physicist d. 1916
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