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tri-(word root) three
Examples of words with the root tri-: tricycle
Abused, Confused, & Misused Words by Mary Embree Copyright © 2007, 2013 by Mary Embree
1. Three: trilobate.
a. Occurring at intervals of three: trimonthly.
b. Occurring three times during: triweekly.
American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
1. three or thrice: triaxial; trigon; trisect.
2. occurring every three: trimonthly.
[from Latin trēs, Greek treis]
Collins English Dictionary – Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014
a combining form meaning “three”: triatomic; trilateral.
[Middle English < Latin, comb. form representing Latin trēs, tria, Greek treîs, tría three]
Random House Kernerman Webster's College Dictionary, © 2010 K Dictionaries Ltd. Copyright 2005, 1997, 1991 by Random House, Inc. All rights reserved.