Pronunciation: (u-lOO'mu-num),[key] —n. Chem.a silver-white metallic element, light in weight, ductile, malleable, and not readily corroded or tarnished, occurring combined in nature in igneous rock, shale, clay, and most soil: used in alloys and for lightweight utensils, castings, airplane parts, etc. Abbr.: alum.; Symbol: Al; at. wt.: 26.98; at. no.: 13; sp. gr.: 2.70 at 20°C.
—adj. of, pertaining to, or containing aluminum: an aluminum frying pan.Also,esp. Brit.,aluminium.