Definition of "indole"

(organic chemistry) An organic compound, C8H7N, found in coal tar, and produced in the gut by the bacterial decomposition of tryptophan; it is an aromatic bicyclic heterocycle having a benzene ring fused with a pyrrole ring; indole and its derivatives occur widely in nature and have many industrial applications.  examples

(organic chemistry) Any of the derivatives of indole1.  examples

(obsolete) guileless