isotherm

/ˈaɪ.səʊˌθɜː(ɹ)m/

AꞮ · səʊθɜː(ɹ)m (2 syllables)

English Noun

Definition

A line on a graph or chart, such as a weather map, along which all the points have the same temperature.

Etymology

From the French isotherme (“of equal temperature”, adjective), itself from Ancient Greek ἴσος (ísos, “equal”) + θέρμη (thérmē, “warmth”). By surface analysis, iso- + -therm.