Kelvin

How to spell kelvin

6 letters · 2 syllables

How to pronounce kelvin

Say the part in capitals loudest.

What does kelvin mean?

1. nounThe base unit of thermodynamic temperature in the International System of Units, measured from absolute zero.

Kelvin in a sentence

• One kelvin equals one degree on the absolute temperature scale.

• The laboratory cooled the sample to within one kelvin of absolute zero.

Where does kelvin come from?

Language of origin: Celtic

This word is an eponym, a unit name minted from the title of the Scottish physicist William Thomson, who in 1892 became Baron Kelvin. He took that title from the River Kelvin, which flows past the University of Glasgow where he worked, and the river's own name is thought to derive from a Gaelic or older Celtic word meaning something like 'narrow water' or 'wooded stream'. Thomson proposed an absolute temperature scale beginning at the coldest possible point, absolute zero, and after his death the unit of that scale was formally named in his honour. The kelvin was adopted as a base unit of the International System of Units in 1954, and unlike degrees Celsius or Fahrenheit it is written without the word 'degree'. Because it honours a person, the unit name is lower case (one kelvin) while its symbol is the capital letter K, a small spelling quirk worth remembering.

How the word is built

• Kelvin (from the surname of Lord Kelvin, itself from the River Kelvin); used as an eponymous unit name