isohyet

/ˈaɪ.soʊˌhaɪ.ɪt/

AꞮ · soʊhaɪ · ɪt (3 syllables)

English Noun

Definition

A line of equal rainfall on a map or chart, such as a weather map.

From iso- + Ancient Greek ὑετός (huetós, “rain”).

"On the yearly rainfall map, the 10-inch (250 mm) isohyet separates viable cropland from desert."