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therm

1 American  
[thurm] / θɜrm /
Or therme

noun

Physics.
  1. any of several units of heat, as one equivalent to 1000 large calories or 100,000 British thermal units.


therm- 2 American  
  1. variant of thermo- before a vowel.

    thermesthesia.


-therm 3 American  
  1. variant of thermo- as final element in compound words.

    isotherm.


therm. 4 American  

abbreviation

  1. thermometer.


therm British  
/ θɜːm /

noun

  1. a unit of heat equal to 100 000 British thermal units. One therm is equal to 1.055 056 × 10 8 joules

"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

Etymology

Origin of therm

First recorded in 1885–90, therm is from the Greek word thérmē heat

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

Oil reached $116.78 a barrel on 9 March, while UK gas reached 162.55p a therm on 3 March.

From BBC • Mar. 18, 2026

British wholesale gas prices have fallen from a peak of 640p per year in August 2022, to around 70p per therm.

From BBC • May 20, 2023

British gas for immediate delivery was up 85 pence to 450 pence per therm at 0940 GMT, while the day-ahead contract rose 119 pence to 480 p/therm.

From Reuters • Aug. 22, 2022

It is currently 8.3% higher at 426.9p per therm, not far from the all-time high of around 450p in December.

From The Guardian • Mar. 3, 2022

It is 251.9 times greater than the metric unit, therm or calorie, which is the amount of heat required to raise one gramme of water from 4 degrees to 5 degrees centigrade.

From The Story of Electricity by Munro, John