from The American Heritage® Dictionary of the English Language, 4th Edition
- n. See rare-earth element.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. Any of the 14 rare earth elements from cerium (or from lanthanum) to lutetium in the periodic table; because their outermost orbitals are empty, they have very similar chemistry; below them are the actinides.
from the GNU version of the Collaborative International Dictionary of English
- n. Any rare earth element of the lanthanide series (atomic numbers 57 through 71).
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- n. any element of the lanthanide series (atomic numbers 57 through 71)
lanthan(um) + -ide.(American Heritage® Dictionary of the English Language, Fourth Edition)