The phrase "hundredth anniversary" refers to a special occasion that happens once every 100 years. It is a celebration of an event or milestone that occurred 100 years ago. Full definition
This exhibition celebrates the two - hundredth anniversary of Brontë's birth in 1816, and marks an historic collaboration between the Morgan, which holds one of the world's most important collections of Brontë manuscripts and letters, and the Brontë Parsonage Museum, in Haworth, England, which has loaned a variety of key items including the author's earliest surviving miniature manuscript, her portable writing desk and paintbox, and a blue floral dress she wore in the 1850s. (themorgan.org)
Kennedy Galleries, New York, Hundredth Anniversary Exhibition of Paintings and Sculptures by One Hundred Artists Associated with the Art Students League of New York, March 6 — 29. (jamesrosenquiststudio.com)
Though the majority of Magna Carta's clauses have since been repealed from British statute books (only Clauses 1, 13, 39 and 40 remain), what Magna Carta stands for, and the way that it has been used, are certainly causes for celebration in this eight - hundredth anniversary year. (blog.politics.ox.ac.uk)