tercentenary[tʉr′sen ten′ər ē, tər sen′tə ner′ē]
tercentenary definition by Webster's New World
Webster's New World College Dictionary Copyright © 2010 by Wiley Publishing, Inc., Cleveland, Ohio. Used by arrangement with John Wiley & Sons, Inc.
tercentenary definition by American Heritage Dictionary
noun pl. ter·cen·ten·a·ries
A 300th anniversary or its celebration.adjective
Of or relating to a span of 300 years or to a 300th anniversary.
Origin: Latin ter, thrice; see tern2 + centenary.