metalloid, n. [L. metallum metal + -oid: cf. F. métalloïde.].
Formerly, the metallic base of a fixed alkali, or alkaline earth; -- applied by Sir Humphrey Davy to sodium, potassium, and some other metallic substances whose metallic character was supposed to be not well defined. [1913 Webster]
metalloid, a.
Having the appearance of a metal. [1913 Webster]
Having the properties of a nonmetal; nonmetallic; acid; negative. [1913 Webster]
metalloid, adj. & n.
--adj. having the form or appearance of a metal.
--n. any element intermediate in properties between metals and non-metals, e.g. boron, silicon, and germanium.