n. [ Gr. tachy`s quick + di`daxis teaching. ] A short or rapid method of instructing. [ R. ] [ 1913 Webster ]

‖n. pl. [ NL., fr. Gr. tachy`s quick + glw^ssa tongue. ] (Zool.) A division of monotremes which comprises the spiny ant-eaters of Australia and New Guinea. See Illust. under Echidna. [ 1913 Webster ]

n. An example of tachygraphy; esp., an ancient Greek or Roman tachygraphic manuscript. [ Webster 1913 Suppl. ]

n. [ Gr. &unr_; a fast writer. ] One who writes shorthand; a stenographer; esp., an ancient Greek or Roman notary. [ Webster 1913 Suppl. ]

{ } a. [ Cf. F. tachygraphique. ] Of or pertaining to tachygraphy; written in shorthand. [ 1913 Webster ]

n. [ Gr. tachy`s quick + -graphy: cf. F. tachygraphie. ] The art or practice of rapid writing; shorthand writing; stenography. I. Taylor (The Alphabet). [ 1913 Webster ]

n. [ Gr. tachy`s quick + ly`ein to dissolve. ] (Min.) A vitreous form of basalt; -- so called because decomposable by acids and readily fusible. [ 1913 Webster ]

n. [ Tachy- + -meter. ] 1. (Surveying) An instrument, esp. a transit or theodolite with stadia wires, for determining quickly the distances, bearings, and elevations of distant objects. [ Webster 1913 Suppl. ]

2. A speed indicator; a tachometer. [ Webster 1913 Suppl. ]

n. The science or use of the tachymeter. -- Ta`chy*met"ric a. [Webster 1913 Suppl.]

n. [ Gr. tachy`s quick + -scope. ] An early form of animated-picture machine, devised in 1889 by Otto Anschütz of Berlin, in which the chronophotographs were mounted upon the periphery of a rotating wheel. [ Webster 1913 Suppl. ]