sesquicentennial means occurring every 150 years. Lexicurio rates it Sui generis — a strength score of 85 out of 100.
sesquicentennial is pronounced /ˌsɛskwɪsɛnˈtɛni.əl/.
Why “sesquicentennial” is a great word
SESQUICENTENNIAL — [Adjective, Noun] Of or relating to a period of 150 years, especially a 150th anniversary. From the Latin combining form sesqui- ("one and a half") and centennial ("of or relating to a hundred years"). Unlike "centennial," which marks the clean completion of a century, or "sesquicentenary," its more common British counterpart, "sesquicentennial" denotes an awkward, hybrid duration. It is the tarnished silver of a commemorative cup passed down through five sets of hands, the faded ink on a founding charter now halfway to its own bicentennial, and the quiet civic pride in a bronze plaque softened to deep green—a monument to the stubborn, unround numbers by which we measure our endurance.
adj
- Occurring every 150 years.
- Of, or relating to a sesquicentenary.
noun
- A 150th anniversary.“The city celebrated its sesquicentennial last year.”