/pray'zee oh dim"ee euhm, pray'see-/ , n. Chem.
a rare-earth, metallic, trivalent element, named from its green salts. Symbol: Pr; at. wt.: 140.91; at. no.: 59; sp. gr.: 6.77 at 20°C.
[ 1880-85; praseo- (comb. form repr. Gk prásios leek-green; see PRASE) + (DI)DYMIUM ]