D defs.my
Entry 1 sense Webster, 1913

Colcothar

/(kŏl"kō̇*thẽr)/ · Col·co·thar · IPA
01 n. Polishing rouge; a reddish brown oxide of iron, used in polishing glass, and also as a pigment; -- called also crocus Martis.
  1. 1.
    Polishing rouge; a reddish brown oxide of iron, used in polishing glass, and also as a pigment; -- called also crocus Martis.(Chem.) Also: crocus Martis