• synonyms


noun Electricity.
  1. an adjustable resistor so constructed that its resistance may be changed without opening the circuit in which it is connected, thereby controlling the current in the circuit.
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Origin of rheostat

First recorded in 1843; rheo- + -stat
Related formsrhe·o·stat·ic, adjective
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

Examples from the Web for rheostat

Historical Examples of rheostat

  • He moved the rheostat under his hand, and the thunder slackened.

    Astounding Stories of Super-Science, June, 1930


  • That gives you your direction, and the rheostat here at the belt changes the velocity.

    Islands of Space

    John W Campbell

  • To the left of this coil was a large relay switch, and a rheostat control.

    The Black Star Passes

    John W Campbell

  • Slowly he closed the rheostat and put the power into the coil.

    The Black Star Passes

    John W Campbell

  • The Commander hobbled toward it, and manipulated a rheostat.

    The Sky Trap

    Frank Belknap Long

British Dictionary definitions for rheostat


  1. a variable resistance, usually consisting of a coil of wire with a terminal at one end and a sliding contact that moves along the coil to tap off the current
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Derived Formsrheostatic, adjective
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for rheostat


1843, coined by English physicist Sir Charles Wheatstone (1802-1875) from Greek rheos "a flowing, stream" (from PIE root *sreu-, see rheum) + -stat "regulating device." Related: Rheostatic.

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Online Etymology Dictionary, © 2010 Douglas Harper

rheostat in Science


  1. See under resistor.
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The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.