Machmeter

English

Etymology tree

English Mach

Proto-Indo-European *meh₁-

Proto-Indo-European *-tḗr

Proto-Indo-European *-trom

Proto-Hellenic *-tron

Ancient Greek -τρον (-tron)

Ancient Greek μέτρον (métron)lbor.

French -mètrebor.

English -meter

English Machmeter

From Mach + -meter.

Machmeter (plural Machmeters)

(aviation) An instrument that measures the speed of an aircraft relative to that of sound and displays it in Mach numbers.
- 2012, Aviation Maintenance Technician Handbook-Airframe Volume 2‎^[1], FAA:
  Many high performance aircraft are equipped with a Machmeter for monitoring Mcrit. The Machmeter is essentially an airspeed instrument that is calibrated in relation to Mach on the dial.

an instrument that measures the speed of an aircraft relative to that of sound and displays it in Mach numbers