Tachymeter
Pronunciation : Ta*chym"e*ter
Part of Speech : n.
Definition : 1. (Surveying) An instrument, esp. a transit or theodolite with stadia wires, for determining quickly the distances, bearings, and elevations of distant objects.
2. A speed indicator; a tachometer.
[Tachy- + -meter.]
Source : Webster's Unabridged Dictionary, 1913