Real Dictionary

zirconium in American English
a hard, ductile, gray or black, metallic chemical element found combined in zircon, etc., and used in alloys, ceramics, the cladding for nuclear fuel in reactors, etc.: symbol, Zr; at. no., 40
noun: a metallic element found combined in zircon, baddeleyite, etc., resembling titanium chemically: used in steel metallurgy, as a scavenger, as a refractory, and as an opacifier in vitreous enamels; at. wt.: 91.22; at. no.: 40; sp. gr.: 6.49 at 20°C

zirconium in British English
noun: a greyish-white metallic element, occurring chiefly in zircon, that is exceptionally corrosion-resistant and has low neutron absorption. It is used as a coating in nuclear and chemical plants, as a deoxidizer in steel, and alloyed with niobium in supercon