hydatismMed.|ˈhaɪdətɪz(ə)m, ˈhɪd-| [ad.Gr. ὑδατισµ-ός, f. *ὑδατίζειν to be watery, f. ὑδατ- water. Cf. F. hydatisme.] A sound produced by motion of effused fluid in a cavity of the body. 1753in Chambers Cycl. Supp.1847in Craig.1854in Mayne Expos.Lex.