heterocyclic

[het-er-uh-sahy-klik, -sik-lik] /ˌhɛt ər əˈsaɪ klɪk, -ˈsɪk lɪk/
adjective, Chemistry
1.
of or pertaining to the branch of chemistry dealing with cyclic compounds in which at least one of the ring members is not a carbon atom (contrasted with homocyclic).
2.
noting such compounds, as ethylene oxide, C 2 H 4 O.
Origin
1895-1900; hetero- + cyclic
Related forms
heterocycle
[het-er-uh-sahy-kuh l] /ˈhɛt ər əˌsaɪ kəl/ (Show IPA), noun
British Dictionary definitions for heterocyclic

heterocyclic

/ˌhɛtərəʊˈsaɪklɪk; -ˈsɪk-/
adjective
1.
(of an organic compound) containing a closed ring of atoms, at least one of which is not a carbon atom Compare homocyclic
heterocyclic in Medicine

heterocyclic het·er·o·cy·clic (hět'ə-rō-sī'klĭk, -sĭk'lĭk)
adj.
Containing more than one kind of atom joined in a ring.

heterocyclic in Science
heterocyclic
  (hět'ə-rō-sī'klĭk, -sĭk'lĭk)   
Of or relating to a compound containing a closed ring structure made of more than one kind of atom. Pyridine (C5H5N), for example, is a heterocyclic compound, as its ring contains five carbon atoms and one nitrogen atom. Compare homocyclic.