ISOTHERM

n. line on a meteorological map connecting areas with the same average temperatures; curve made up of dots representing the same temperature (Physics)

An isotherm may refer to:A type of contour line connecting points of equal temperatureAn isothermal process in a thermodynamic cycle.
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Noun
1. an isogram connecting points having the same temperature at a given time
(hypernym) isogram, isopleth, isarithm

adj. isothermal, pertaining to an isotherm, of a line which connects areas with the same average temperatures (Meteorology)

(n.)
A line connecting or marking points on the earth's surface having the same temperature. This may be the temperature for a given time of observation, or the mean temperature for a year or other period. Also, a similar line based on the distribution of temperature in the ocean.