Dictionary.com
Thesaurus.com

octocentenary

American  
[ok-toh-sen-ten-uh-ree, -sen-tn-er-ee, -sen-tee-nuh-ree] / ˌɒk toʊ sɛnˈtɛn ə ri, -ˈsɛn tnˌɛr i, -sɛnˈti nə ri /

adjective

  1. pertaining to 800 or a period of 800 years; marking the completion of 800 years.


noun

PLURAL

octocentenaries
  1. an 800th anniversary or its celebration.

octocentenary British  
/ ˌɒktəʊsɛnˈtiːnərɪ /

noun

  1. an eight-hundredth anniversary

"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 octocentenary

First recorded in 1885–90; octo- + centenary