Thermostat

How to spell thermostat

10 letters · 3 syllables

How to pronounce thermostat

Say the part in capitals loudest.

What does thermostat mean?

1. nounA device that automatically regulates temperature by switching heating or cooling on and off to keep it constant.

Thermostat in a sentence

• He turned the thermostat down to save on the heating bill.

• The new smart thermostat learns your daily routine and adjusts the heat.

Where does thermostat come from?

Language of origin: Greek

Thermostat is a nineteenth-century scientific coinage built entirely from Greek parts. The first half comes from therme, the Greek word for heat or warmth, which also gives English words such as thermometer and thermal. The second half comes from statos, meaning standing or made to stand still, from the verb histanai, to cause to stand; the same -stat element appears in words like 'rheostat'. Put together the parts literally describe a device that makes heat stand steady, that is, keeps a temperature constant. The term was coined in the 1830s for the early heat-regulating instruments, and the modern household sense, the dial or panel that controls central heating, became common in the twentieth century. The Greek roots are why the word keeps its 'th' and ends in -stat rather than the more phonetic-looking 'state'.

How the word is built

• thermo- (from Greek therme: heat)
• -stat (from Greek statos: standing, stationary, kept constant)