a combining form meaning “good,” “well,” occurring chiefly in words of Greek origin (eupepsia); in scientific coinages, especially taxonomic names, it often has the sense “true, genuine” (eukaryote)
Origin of eu-
< Greek, combining form of eús good (adj.) or eú, eû (neuter, used as adv.) well
word-forming element in modern use meaning "good, well," from comb. form of Greek eus "good," eu "well" (adv.), also "luckily, happily," from PIE *(e)su- "good" (cf. Sanskrit su- "good," Avestan hu- "good").
A very rare, silvery-white metallic element that is the softest member of the lanthanide series. It is used in making color television tubes and lasers and as a neutron absorber in nuclear research. Atomic number 63; atomic weight 151.96; melting point 826°C; boiling point 1,439°C; specific gravity 5.259; valence 2, 3. See Periodic Table.
