tricyclic compound /trīsik″lik/ [Gk, treis + kyklos, circle; L, componere, to put together] , a chemical substance containing three rings in the molecular structure, especially a tricyclic antidepressant drug used in the treatment of reactive or endogenous depression. These drugs also have anticonvulsant, antihistaminic, anticholinergic, hypotensive, and sedative effects. See also antidepressant.
