An"ti*mo*ny (?; 112), n. [LL. antimonium, of unknown origin.] (Chem.) An elementary substance, resembling a metal in its appearance and physical properties, but in its chemical relations belonging to the class of nonmetallic substances. Atomic weight, 120. Symbol, Sb.

&fist; It is of tin-white color, brittle, laminated or crystalline, fusible, and vaporizable at a rather low temperature. It is used in some metallic alloys, as type metal and bell metal, and also for medical preparations, which are in general emetics or cathartics. By ancient writers, and some moderns, the term is applied to native gray ore of antimony, or stibnite (the stibium of the Romans, and the sti`mmi of the Greeks, a sulphide of antimony, from which most of the antimony of commerce is obtained. Cervantite, senarmontite, and valentinite are native oxides of antimony.

• a chemical element (symbol Sb) with an atomic number of 51. The symbol is derived from the Latin stibium.