from The American Heritage® Dictionary of the English Language, 4th Edition
- n. An instrument used to measure the rotations per minute of a rotating shaft.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. A device for measuring the revolutions per minute (RPMs) of a revolving shaft, as with the driveshaft of an automobile.
- n. A device for measuring or indicating velocity or speed, as of blood, a river, a machine, etc.
from the GNU version of the Collaborative International Dictionary of English
- n. An instrument for measuring the velocity, or indicating changes in the velocity, of a moving body or substance.
- n. An instrument for measuring the velocity of running water in a river or canal, consisting of a wheel with inclined vanes, which is turned by the current. The rotations of the wheel are recorded by clockwork.
- n. An instrument for showing at any moment the speed of a revolving shaft, consisting of a delicate revolving conical pendulum which is driven by the shaft, and the action of which by change of speed moves a pointer which indicates the speed on a graduated dial.
- n. An instrument for measuring the velocity of the blood; a hæmatachometer.
from The Century Dictionary and Cyclopedia
- n. An instrument for measuring velocity.
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- n. measuring instrument for indicating speed of rotation
Greek takhos, speed + -meter.(American Heritage® Dictionary of the English Language, Fourth Edition)
Greek tachy-, 'fast' + -meter (Wiktionary)