ˈkaləməl, -ˌmel noun
( -s )
Etymology: probably from (assumed) New Latin calomelas, from calo- + Greek melas black — more at mullet
: a white tasteless salt Hg 2 Cl 2 found in nature as a sectile tetragonal mineral (hardness 1.5, specific gravity 7.15), obtained as a heavy powder by precipitation from solution or by sublimation of a mixture of mercury and chlorine, and used as a cathartic, fungicide, and insecticide — called also mercurous chloride