celtium

celtium (uncountable)

1. (historical) The name originally proposed for element 72, now called hafnium; the discoverer, Georges Urbain, conjectured it to be a rare earth element, and proposed the symbol Ct; but subsequent work showed it to be a transition element, and hafnium was given the symbol Hf.

• keltium (symbol Kt)

celtium n (genitive celtiī or celtī); second declension

1. carapace, tortoise shell

Second-declension noun (neuter).

¹Found in older Latin (until the Augustan Age).