1 of 3


: a unit for quantity of heat that equals 100,000 British thermal units


2 of 3

combining form

variants or thermo-
: heat
: thermoelectric


3 of 3

noun combining form

: animal having a (specified) body temperature

Example Sentences

Recent Examples on the Web
The utility recently warned its 905,000 customers equipped with gas appliances that their January bills are estimated to double, from $2.55 per therm in December to $5.11 in January, due to a spike in wholesale prices in California. San Diego Union-Tribune, 21 Jan. 2023 San Diego Gas & Electric’s rate for natural gas has doubled compared to last month, with the price per therm jumping from $2.55 in December to $5.11 in January. San Diego Union-Tribune, 6 Jan. 2023 The rate for natural gas has doubled compared with last month, with the price per therm jumping from $2.55 in December to $5.11 in January. Los Angeles Times, 6 Jan. 2023 At Nicor Gas, the price was 63 cents per therm in October — the lowest natural gas prices in the Chicago area. Robert Channick,, 14 Oct. 2021 And considering that the SoCalGas core procurement price for October came in 13 cents per therm higher than September, prices will increase again. Rob Nikolewski, San Diego Union-Tribune, 8 Oct. 2021 The top rate for electricity is more than 40 cents per kilowatt hour, which equates to nearly $12 per therm of heat. WSJ, 23 Dec. 2020 Natural gas, by contrast, costs about $2.50 a therm. WSJ, 23 Dec. 2020 Typical residential customers of NW Natural using 54 therms per month will see their bill increase by $2.31, or 4.4%, from $52.43 to $54.74. USA TODAY, 4 Nov. 2019 See More

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'therm.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

Word History



Greek thermē heat, from thermos hot; akin to Latin formus warm, Sanskrit gharma heat

Combining form

Greek, from thermē

Noun combining form

Greek thermē heat

First Known Use


1888, in the meaning defined above

Time Traveler
The first known use of therm was in 1888

Dictionary Entries Near therm

Cite this Entry

“Therm.” Dictionary, Merriam-Webster, Accessed 29 Jan. 2023.

Medical Definition


: any of several units of quantity of heat: as
: 1000 kilogram calories
: 100,000 British thermal units

More from Merriam-Webster on therm

Last Updated: - Updated example sentences
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