adjective
hydrothermal
Etymology tree Proto-Indo-European *wed- Proto-Indo-European *-r̥ Proto-Indo-European *wódr̥ Proto-Hellenic *údōr Ancient Greek ῡ̆̔́δωρ (hū̆́dōr) Ancient Greek ῠ̔δρο- (hŭdro-)der. Spanish hidro- Spanish termas Proto-Indo-European *h₂el-der.? Proto-Italic *-ālis Latin -ālis Spanish -al Spanish termal Spanish hidrotermal From hidro- + termal.