Phreatic

The adjective phreatic ( ancient Greek φρέαρ phréar ( genitive φρέατος phréatos ), fountain ' ) refers to:

Phreatisches water, see groundwater
Water-filled caves, cave see Phreatic and vadose caves #
Phreatic in volcanology generally steam explosions, where superheated water due to a sudden depressurization to steam, see exploded