ˈlithēəm noun
( -s )
Etymology: New Latin, from lith- + -ium
: a soft silver-white univalent element of the alkali metal group that is the lightest metal known, that occurs combined in several minerals (as amblygonite, spodumene, lepidolite, zinnwaldite), in many mineral waters, and in plant ashes, that is obtained as the metal by electrolysis of fused lithium chloride, and that is used chiefly in nuclear reactions, in metallurgy for removing gases from molten metals and making light alloys, and in the manufacture of lithium compounds — symbol Li ; see element table