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tricyclic

[ trahy-sahy-klik, -sik-lik ]
/ traɪˈsaɪ klɪk, -ˈsɪk lɪk /
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adjective
pertaining to or embodying three cycles.
noun
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.
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Origin of tricyclic

First recorded in 1890–95; tri- + cyclic
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2021

British Dictionary definitions for tricyclic

tricyclic
/ (traɪˈsaɪklɪk) /

adjective
(of a chemical compound) containing three rings in the molecular structure
noun
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

Scientific definitions for tricyclic

tricyclic
[ trī-sīklĭk, -sĭklĭk ]

Relating to a chemical compound having three closed rings. Anthracene is a tricyclic hydrocarbon.
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.
Composed of or arranged in three distinct whorls, as the petals of a flower.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
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