adjective. Containing more than one kind of atom joined in a ring.

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:

adjective. Having one or more atoms other than carbon in at least one of its rings.

noun. A heterocycle

noun. a compound containing a heterocyclic ring

adjective. containing a closed ring of atoms of which at least one is not a carbon atom

"Cooking meats with charcoal or gas grills can cause the formation of compounds called heterocyclic amines (HCAs) and polycyclic aromatic hydrocarbons (PAHs)."

alkaloid  anthocyanin  azole  dioxin  flavone  

cyclic  

heterocycle  

albuminous  benzenoid  carbon-based  electrophilic  five-membered