the.com/centennial

The birthday that requires a parade, a plaque, and at least one person older than it.

means An event marking the 100th anniversary of something — or, as an adjective, describing something that has lasted or occurred a full century.

from Built from Latin centum, 'hundred,' plus annus, 'year' — the same 'annus' that gives us annual and anniversary. The word is American in flavor, rising to prominence around the 1876 celebration of a hundred years of U.S. independence, which helped stamp 'centennial' into everyday vocabulary as the go-to word for grand, round-number birthdays.

origin
Latin centum plus annus, hundred years
first big one
US centennial, 1876, debuted the telephone
next up
Many flags, nations, companies turning 100 this decade
bonus term
sesquicentennial means you waited 150 years
the.com · every word