The story
Blend of sesterce (a two and a half coin) + centennial, or from Latin sēster(tius) + centennial.
First known use, by meaning
- from the 1980s A 250th anniversary.
Etymology from Wiktionary, CC BY-SA 4.0.
sestercentennial
Today it means: A 250th anniversary. Full definition →
First used the 1980s