• synonyms


[pir-i-deen, -din]
noun Chemistry.
  1. a colorless, flammable, liquid organic base, C5H5N, having a disagreeable odor, usually obtained from coal or synthesized from acetaldehyde and ammonia: used chiefly as a solvent and in organic synthesis.
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Origin of pyridine

First recorded in 1850–55; pyr- + -id3 + -ine2
Related formspy·rid·ic [pahy-rid-ik] /paɪˈrɪd ɪk/, adjective
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

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British Dictionary definitions for pyridine


  1. a colourless hygroscopic liquid with a characteristic odour. It is a basic heterocyclic compound containing one nitrogen atom and five carbon atoms in its molecules and is used as a solvent and in preparing other organic chemicals. Formula: C 5 H 5 N
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Word Origin

C19: from pyro- + -id ³ + -ine ²
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

pyridine in Medicine


  1. A flammable, colorless or yellowish liquid base that results from the dry distillation of organic matter containing nitrogen, has a penetrating odor, and is used in analytical chemistry and in the manufacture of various drugs and vitamins.
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Related formspy•ridic (pī-rĭdĭk) adj.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.

pyridine in Science


  1. Any of a class of organic compounds containing a six-member ring in which one of the carbon atoms has been replaced by a nitrogen atom. Pyridines include compounds used as water repellents, herbicides, and various drugs. The pyridine ring structure is also part of many larger compounds, including niacin and nicotine.
  2. The simplest of these compounds, a flammable, colorless or yellowish liquid base having a penetrating odor. It is used as a solvent and waterproofing agent and in the manufacture of various drugs and vitamins. Chemical formula: C5H5N.
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The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.