A ceremony or celebration occurring every three years.(noun)
American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Use "triennial" in a sentence
"The Finns won attention with their performances in triennial tests sponsored by the Organization for Economic Cooperation and Development, a group funded by 30 countries that monitors social and economic trends."
"However, important factors such as triennial property assessments and the homestead property tax cap, which limits taxable AV growth to"
"The Anglican Church of Canada is pleased to announce that for the first time in its 117 year history, General Synod is offering religious based organizations and affiliates the opportunity to support its triennial national convention through a variety of unique sponsorship initiatives."