from The American Heritage® Dictionary of the English Language, 4th Edition
- adj. Containing more than one kind of atom joined in a ring.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- adj. Having one or more atoms other than carbon in at least one of its rings.
- n. A heterocycle
from The Century Dictionary and Cyclopedia
- In chem., of a substance the molecule is believed to consist of a ring or continuous chain of atoms, containing in such a ring atoms of more than a single element. Thus the molecule of pyridine consists of a ring of six atoms consecutively united with each other, five of these atoms being of carbon and one of nitrogen (each carbon atom having also a hydrogen atom attached to it)—thus:
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- n. a compound containing a heterocyclic ring
- adj. containing a closed ring of atoms of which at least one is not a carbon atom
hetero- + cyclic (Wiktionary)