Where does “hydrothermally” come from?
hydrothermally (English) comes from English hydrothermal, from English thermal, from French thermal, from New Latin thermalis, from Ancient Greek Θέρμη, from Proto-Indo-European gʷʰer-, from Proto-Indo-European gʷʰe-gʷʰór-e ~ gʷʰe-gʷʰr-ḗr.
hydrothermally (English): By hydrothermal means
Ancestry of “hydrothermally”, step by step