Eu
Eu , noun
(Chemistry) the chemical symbol for Europium, an element with atomic number 63 and atomic weight 151.96.
Eu
[Greek e'y^ well, orig. neut. of e'y`s good; prob. connected with Sanskrit su, from the same root as English is; or with Sanskrit vasu good, prob. from the same root as English was.]
A prefix used frequently in composition, signifying well, good, advantageous; -- the opposite of dys-.