- a line on a map connecting points on the earth's surface having the same mean temperature or the same temperature at a given time
- a line representing changes of volume or pressure at constant temperature
Origin of isothermFrench isotherme from iso-, iso- + Classical Greek therm?, heat from thermos, hot: see warm
Origin of isothermFrom French isotherme having the same temperature Greek īso- iso- Greek thermē heat ; see -therm .
- A line of equal or constant temperature on a graph or chart, such as a weather map.
From the French adjective isotherme (“of equal temperature”), itself from Ancient Greek ἴσος (isos, “equal”) + θέρμη (thermē, “warmth”)