Main Entry: iso·pleth

Pronunciation: \ˈī-sə-ˌpleth\

Function: noun

Etymology: International Scientific Vocabulary is- + Greek plēthos quantity; akin to Greek plēthein to be full — more at full

Date: 1908

1 : an isoline on a graph showing the occurrence or frequency of a phenomenon as a function of two variables
2 : a line on a map connecting points at which a given variable has a specified constant value

— iso·pleth·ic \ˌī-sə-ˈple-thik\ adjective