a bluish-white, metallic chemical element, often a supercooled liquid at room temperature, used in semiconductors, LED's, lasers, etc., and as a substitute for mercury in high-temperature thermometers: symbol, Ga; at. no., 31
See gallium in American Heritage Dictionary 4
(gălˈē-əm)
noun Symbol Ga
A rare metallic element that is liquid near room temperature, expands on solidifying, and is found as a trace element in coal, bauxite, and other minerals. It is used in semiconductor technology and as a component of various low-melting alloys. Atomic number 31; atomic weight 69.72; melting point 29.78°C; boiling point 2,403°C; specific gravity 5.907; valence 2, 3. See Table at element.