tricyclic: an antidepressant drug that acts by blocking the reuptake of norepinephrine and serotonin and thus making more of those substances available to act on receptors in the brain
antidepressant: any of a class of drugs used to treat depression; often have undesirable side effects
subordinate clause: a clause in a complex sentence that cannot stand alone as a complete sentence and that functions within the sentence as a noun or adjective or adverb