thermostat

UK: /ˈθɜː^rməstæt/ US: /ˈθɝməˌstæt/ ,(thûr′mə stat′)

Inflections of 'thermostat' (v): (⇒ conjugate)

thermostats

v 3rd person singular

thermostatting

v pres p

thermostating

v pres p

thermostatted

v past

thermostated

v past

thermostatted

v past p

thermostated

v past p

WordReference Random House Learner's Dictionary of American English © 2026

ther•mo•stat /ˈθɜrməˌstæt/   n. [countable]

1. Thermodynamics a device that measures temperature and automatically turns on or off a heating or cooling device:
   The thermostat in the furnace didn't work properly.

ther•mo•stat•ic, adj. 
ther•mo•stat•i•cal•ly, adv. See -stat-,-therm-.

WordReference Random House Unabridged Dictionary of American English © 2026

ther•mo•stat  (thûr′mə stat′), n., v., -stat•ted or -stat•ed;
-stat•ting or -stat•ing. 
n. 

1. Thermodynamics 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.

v.t. 

2. Thermodynamics to equip or control with a thermostat.

• thermo- + -stat 1825–35

ther′mo•stat′ic, adj. 
ther′mo•stat′i•cal•ly, adv. 

Collins Concise English Dictionary © HarperCollins Publishers::

thermostat / ˈθɜːməˌstæt/ noun

1. 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
2. a similar device that actuates equipment, such as a sprinkler, when a certain temperature is reached

ˌthermoˈstatic adjective

ˌthermoˈstatically adverb