from The American Heritage® Dictionary of the English Language, 4th Edition
- adj. Having four atoms per molecule.
- adj. Having four replaceable univalent atoms or radicals.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- adj. consisting of four atoms
from the GNU version of the Collaborative International Dictionary of English
- adj. Consisting of four atoms; having four atoms in the molecule, as phosphorus and arsenic.
- adj. Having a valence of four; quadrivalent; tetravalent; sometimes, in a specific sense, having four hydroxyl groups, whether acid or basic.
from The Century Dictionary and Cyclopedia
- Same as tetradic.
Sorry, no etymologies found.
It is worthy of notice that in diatomic elements _four_ funnels open on the faces of tetrahedra; in triatomic, _six_ funnels on the faces of cubes; in tetratomic, _eight_ funnels on the faces of octahedra.