noun, feminine/i.dʁɔ.mɑ̃.si/plural: hydromancies
hydromancy
From Middle French hydromancie, from Old French hydromancie, from Late Latin hydromantīa, from Ancient Greek ὑδρομαντεία (hudromanteía), compound of ὑδρο- (hudro-, “hydro-, water”) + μαντεία (manteía, “divination”).