• synonyms


See more synonyms for trigonal on Thesaurus.com
  1. of, relating to, or shaped like a triangle; having three angles; triangular.
  2. Crystallography. having threefold symmetry.
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Origin of trigonal

First recorded in 1560–70; trigon + -al1
Related formstrig·o·nal·ly, adverbsub·trig·o·nal, adjective
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

Related Words for trigonal

trilateral, treble, triple, ternary, third, trinitarian, triangular, pyramidal, ternate, trichotomous, trigonal, trigonous, trinal, trinary, tripartite, cuneate, deltoid, deltoidal, hastate, pyriform

Examples from the Web for trigonal

Historical Examples of trigonal

British Dictionary definitions for trigonal


  1. another word for triangular (def. 1)
  2. Also: rhombohedral relating or belonging to the crystal system characterized by three equal axes that are equally inclined and not perpendicular to each other
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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

trigonal in Science


  1. Relating to a crystal having three axes of equal length intersecting at oblique angles. This crystal system is considered a subset of the hexagonal system. The mineral quartz has trigonal crystals. Also called rhombohedral See illustration at crystal.
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The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.