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tercentenary

American  
[tur-sen-ten-uh-ree, tur-sen-tn-er-ee, tur-sen-tee-nuh-ree] / ˌtɜr sɛnˈtɛn ə ri, tɜrˈsɛn tnˌɛr i, ˌtɜr sɛnˈti nə ri /
Or tercentennial

adjective

plural

tercentenaries

  1. tricentennial.

tercentenary British  
/ ˌtɜːsɛnˈtiːnərɪ /

adjective

  1. of or relating to a period of 300 years

  2. of or relating to a 300th anniversary or its celebration

"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

noun

  1. an anniversary of 300 years or its celebration

"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

Etymology

Origin of tercentenary

First recorded in 1835–45; ter- + centenary

Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.