Definition of machs:
(n) :
(physics, uncountable) A ratio of the speed (of an object, etc.) to the speed of sound in the fluid or other medium through which the object travels. Usually used to describe supersonic speeds; always precedes the Mach number.
(n) :
Ernst Mach, Austrian physicist (1838–1916), born in Moravia (now Czech Republic).
(n) :
A surname from Czech.
(n) :
(informal, countable) Clipping of Machiavellian. [An unscrupulous schemer.]