tricyclic antidepressant
noun(tricyclic antidepressant)
any of a group of antidepressant drugs (such as imipramine and amitriptyline) that contain three fused benzene rings, potentiate the action of catecholamines (such as norepinephrine and serotonin) by inhibiting their uptake by nerve endings, and do not inhibit the action of monoamine oxidase —called also tricyclic