from The American Heritage® Dictionary of the English Language, 4th Edition
- n. The average mass of an atom of an element, usually expressed relative to the mass of carbon 12, which is assigned 12 atomic mass units.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. Former term for the more specific relative atomic mass.
- n. A term used to represent the mean relative atomic mass of an element in nature, as distinct from the relative atomic mass of a single isotope.
from the GNU version of the Collaborative International Dictionary of English
- adj. the weight of the atom of an element as compared with the weight of the atom of hydrogen, taken as a standard.
- n. See under Atomic, and cf. Element.
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- n. (chemistry) the mass of an atom of a chemical element expressed in atomic mass units
Sorry, no etymologies found.
"Iridium," said the Saint encyclopedically, "is an element with an atomic weight of 193.1.