n. [ Pref. met- + acetone. ] (Chem.) A colorless liquid of an agreeable odor, C6H10O, obtained by distilling a mixture of sugar and lime; -- so called because formerly regarded as a polymeric modification of acetone. [ 1913 Webster ]

‖v. impers. [ L., it is silent, 3d pers.pr. of tacere to be silent. ] (Mus.) It is silent; -- a direction for a vocal or instrumental part to be silent during a whole movement. [ 1913 Webster ]