What is the X in X-mas?
quinoline quin·o·line (kwĭn'ə-lēn', -lĭn)
An aromatic organic base synthesized or obtained from coal tar and used as a food preservative and in making antiseptics.
any of a class of organic compounds of the aromatic heterocyclic series characterized by a double-ring structure composed of a benzene and a pyridine ring fused at two adjacent carbon atoms. The benzene ring contains six carbon atoms, while the pyridine ring contains five carbon atoms and a nitrogen atom. The simplest member of the quinoline family is quinoline itself, a compound with molecular structure C9H7N.