- noun a soft silvery-white metallic element of the lanthanide group, derived from monazite and bastnaesite and used in lasers
- A steel-gray reactive metallic chemical element with atomic number 63. it is soft and malleable, and has nearly 30 known isotopes, of which 2 are stable. Used, for instance, as a phosphor activator, and as a neutron absorber in nuclear reactors. Its chemical symbol is Eu.
- chemical symbolEu
- prefix good, well