uranium Definition

uranium
noun

1. chem.
(symbol U, atomic number 92) a dense silvery-white radioactive metallic element, originally discovered in pitchblende in 1789, but now mainly obtained from the ore uraninite. It is chiefly used to produce nuclear energy, as a fuel for nuclear reactors and nuclear weapons, by fission of the isotope uranium-235.

Derivative: uranic
adj

Etymology: 18c: named after the planet Uranus, discovered shortly before the metal; see Uranian.