In chemistry, a cyclic compound is a compound in which a series of atoms is connected to form a loop or ring.

a heterocyclic compound having a metal ion attached by coordinate bonds to at least two nonmetal ions

a breakdown product of creatine phosphate in muscle.

a heterocyclic aromatic organic compound the formula C4H4NH which occurs in the form of a colorless volatile liquid that darkens readily upon exposure to air.

a structural isomer of quinoline.

an organic compound with the molecular formula (CH2)5NH.