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[trahy-sahy-klik, -sik-lik] /traɪˈsaɪ klɪk, -ˈsɪk lɪk/
pertaining to or embodying three cycles.
Also called tricyclic antidepressant. Pharmacology. any of a group of pharmacologically active substances, as imipramine, that share a common three-ring structure, used to treat depression and cocaine abuse.
Origin of tricyclic
1890-95; tri- + cyclic Unabridged
Based on the Random House Dictionary, © Random House, Inc. 2015.
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Examples from the web for tricyclic
  • Of course caffeine in excess provokes seizures in these people, as do numerous other drugs including tricyclic anti depressants.
  • Amitriptyline hydrochloride is a type of prescription medicine called a tricyclic antidepressant.
  • Patients with severe pain that does not respond to tricyclic antidepressants may need powerful painkilling opioid drugs.
  • If patients do not respond to these drugs, tricyclic antidepressants may be helpful.
  • Doxepin is a type of medication called a tricyclic antidepressant.
  • tricyclic antidepressants or anticonvulsant medications may help stabbing pains.
  • For example, tricyclic antidepressants are not approved for use in teens.
British Dictionary definitions for tricyclic


(of a chemical compound) containing three rings in the molecular structure
an antidepressant drug having a tricyclic molecular structure
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition
© William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins
Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
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tricyclic in Science
  (trī-sī'klĭk, -sĭk'lĭk)   
  1. Relating to a chemical compound having three closed rings. Anthracene is a tricyclic hydrocarbon.

  2. Relating to a class of drugs used to treat depression and having a tricyclic chemical structure consisting of two benzene rings fused to opposite sides of a seven-member ring. The seven-member ring consists of six carbon atoms and one nitrogen atom. Tricyclic antidepressants enhance the activity of monoamine neurotransmitters in the brain by inhibiting their reuptake by the cells that secrete them.

  3. Composed of or arranged in three distinct whorls, as the petals of a flower.

The American Heritage® Science Dictionary
Copyright © 2002. Published by Houghton Mifflin. All rights reserved.
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