Now, one of several elementary substances which in the free state are unlike metals, and whose compounds possess or produce acid, rather than basic, properties; a nonmetal; as, boron, carbon, phosphorus, nitrogen, oxygen, sulphur, chlorine, bromine, etc., are metalloids.
(4) a class of elements chemically intermediate in properties between metals and non-metals including boron, silicon, germanium, arsenic and tellurium. Electrical semi-conductors and their oxides are amphoteric (capable of acting either as an acid or a base). Also called semi-metals.