geothermal

adj

Etymology: Etymology tree Pre-Greek der. Proto-Hellenic *gayader. Ancient Greek γαῖᾰ (gaîă)clip. Ancient Greek γῆ (gê) Ancient Greek -ο- (-o-) Ancient Greek γεω- (geō-)der. English geo- English thermal English geothermal From geo- + thermal.

1. Pertaining to heat energy extracted from reservoirs in the earth's interior.