isotherm
noun
iso·therm
ˈī-sə-ˌthərm 
1
: a line on a map or chart of the earth's surface connecting points having the same temperature at a given time or the same mean temperature for a given period
2
: a line on a chart representing changes of volume or pressure under conditions of constant temperature
Examples of isotherm in a Sentence
Recent Examples on the Web
Joining the exodus were a 70-year-old Syrian grandmother with only flip-flops to protect her feet from piercing cold and a six-day-old baby from Afghanistan wrapped in an isotherm bag.
—
David Gauthier-Villars, WSJ, 4 Mar. 2020
The isotherm lines on Humboldt’s map had ups and downs that deviated from lines of latitude.
—Greg Miller, Smithsonian, 16 Oct. 2019
Both locations sit at something called a zero degree isotherm, where the average air temperature hovers right around the freezing point of water.
—Megan Molteni, WIRED, 30 Aug. 2016
Examples are automatically compiled from online sources to
show current usage.
Read More
Opinions expressed in the examples do not represent those of Merriam-Webster or its editors.
Send us feedback.
David Gauthier-Villars, WSJ, 4 Mar. 2020
The isotherm lines on Humboldt’s map had ups and downs that deviated from lines of latitude.
—Greg Miller, Smithsonian, 16 Oct. 2019
Both locations sit at something called a zero degree isotherm, where the average air temperature hovers right around the freezing point of water.
—Megan Molteni, WIRED, 30 Aug. 2016
Cite this Entry
“Isotherm.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/isotherm. Accessed 22 Jul. 2025.
Copy CitationKids Definition
isotherm
noun
iso·therm
ˈī-sə-ˌthərm
: a line on a map connecting points having the same temperature
Medical Definition
isotherm
noun
iso·therm
ˈī-sə-ˌthərm
: a line on a chart representing changes of volume or pressure under conditions of constant temperature
Love words? Need even more definitions?
Merriam-Webster unabridged
Share