Meaning of "Mach meter"

an instrument in an aircraft indicating airspeed as a Mach number.

Mach·me·ter

mäk′mē′tər

Machmeter

(mäk'mē 'Tər)
n.
An airplane instrument that indicates speed in Mach numbers.

Machmeter

ˈmækˌmiːtə

Machmeter

( mækˌmiːtə )
n
(Aeronautics) an instrument to measure the Mach number of an aircraft in flight