of, relating to, or shaped like a triangle; having three angles; triangular.
Crystallography. having threefold symmetry.
- trig·o·nal·ly, adverb
- sub·trig·o·nal, adjective
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
How to use trigonal in a sentence
Orifice either large and rounded-trigonal, or small and oval, either entire or less frequently toothed.A Monograph on the Sub-class Cirripedia (Volume 2 of 2) | Charles Darwin
Parietes ribbed, mottled purplish-red; orifice broad, trigonal, hardly toothed.A Monograph on the Sub-class Cirripedia (Volume 2 of 2) | Charles Darwin
The horns are trigonal, laterally compressed and knotted on the upper edge.Natural History of the Mammalia of India and Ceylon | Robert A. Sterndale
When the whorls are angulated, a trigonal aperture is the result, as in many species of Trochus.A Conchological Manual | George Brettingham Sowerby
Mactracea (plates, fig. 77 to 88), the cartilage placed in a trigonal pit, with a small external ligament.A Conchological Manual | George Brettingham Sowerby
British Dictionary definitions for trigonal
another word for triangular (def. 1)
Also: rhombohedral relating or belonging to the crystal system characterized by three equal axes that are equally inclined and not perpendicular to each other
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 trigonal
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.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.