a device, including a relay actuated by thermal conduction or convection, that functions to establish and maintain a desired temperature automatically or signals a change in temperature for manual adjustment.

verb (used with object), ther·mo·stat·ted or ther·mo·stat·ed; ther·mo·stat·ting or ther·mo·stat·ing.

to equip or control with a thermostat.

Origin of thermostat

First recorded in 1825–35; thermo- + -stat
Related formsther·mo·stat·ic, adjectivether·mo·stat·i·cal·ly, adverb Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Related Words for thermostat

manager, instrument, director, switch, valve, governor, regulator, indicator

Examples from the Web for thermostat

Contemporary Examples of thermostat

  • Just consider the ubiquity of the products: the Honeywell thermostat, the Saul Bass credit scenes.

    The Daily Beast logo
    How Jews Created American Modernism

    Andrew Romano

    August 1, 2014

  • The hipster former Apple guys who reinvented the thermostat have come up with the next big thing: a smoke alarm.

    The Daily Beast logo
    How to Hack the Perfect Home

    Daniel Gross

    November 15, 2013

  • “I wanted to be able to control the thermostat, the attitudes, and the numbers,” he says, and got his wish.

    The Daily Beast logo
    Inside an Oklahoma Abortion Clinic

    Allison Yarrow

    January 22, 2013

Historical Examples of thermostat

British Dictionary definitions for thermostat



a device that maintains a system at a constant temperature. It often consists of a bimetallic strip that bends as it expands and contracts with temperature, thus breaking and making contact with an electrical power supply
a similar device that actuates equipment, such as a sprinkler, when a certain temperature is reached
Derived Formsthermostatic, adjectivethermostatically, adverb
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 thermostat

1831, from thermo- + -stat.

Online Etymology Dictionary, © 2010 Douglas Harper

thermostat in Science



A device that automatically controls heating or cooling equipment in such a way as to maintain a temperature at a constant level or within a specified range, generally using a thermometer capable of triggering electrical switches that activate or deactivate the equipment.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

thermostat in Culture


A device that monitors and automatically responds to changes in temperature and activates switches controlling devices such as furnaces or air conditioners.

The New Dictionary of Cultural Literacy, Third Edition Copyright © 2005 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.