Thermometer

How to spell thermometer

11 letters · 4 syllables

How to pronounce thermometer

Say the part in capitals loudest.

What does thermometer mean?

1. nounAn instrument for measuring temperature, typically a graduated glass tube or a digital sensor.

Thermometer in a sentence

• The nurse placed a thermometer under his tongue to check his fever.

• A kitchen thermometer helps you confirm the roast has reached a safe internal temperature.

Where does thermometer come from?

Language of origin: Greek

The word comes from two Greek elements: thermos, meaning 'warm' or 'hot', and metron, meaning 'a measure'. It entered English in the seventeenth century, around the 1620s to 1630s, as scientists in Italy and northern Europe began building sealed glass instruments to track changes in temperature; the device and its name spread through Latin scientific writing of the period. The thermos- element is the same one that gives us 'thermal' and the brand name Thermos for an insulated flask, while -meter sits inside a whole family of measuring words such as 'barometer' and 'speedometer'. The spelling trap lives in the unstressed middle and ending: the 'mo' is a faint schwa, and the word ends '-meter' rather than the noisy '-metre', so writers sometimes drop or swap the vowels. Remembering that it literally means 'heat measure' anchors both halves of the spelling.

How the word is built

• thermo- (from Greek thermos: warm, hot)
• -meter (from Greek metron: measure)