What is the word for 250th anniversary?

In 1876, America celebrated its centennial. In 1926, she celebrated a sesquicentennial, and in 1976, a bicentennial.

Is there a commonly accepted word to designate a 250th anniversary, or are we going to be stuck with fifty years to the tricentennial?

This is an easy one.

Thank you.

If you’d like to see some government usage, take a look at the US Mint site, which they call 250 years semiquincentennial. If you remember bicentennial coins, you’ll probably also see semiquincentennial coins.

https://www.usmint.gov/coins/coin-programs/semiquincentennial/?srsltid=AfmBOoqxJ9mMdBnbKVBp7QcjTtlZO7Ub8i1vOPfHTIrvKxx-UnYbETA4

There’s already a thread on this.

Oh. I thought I went insane, for a minute.
I knew I remembered it.

Semiquincentennial, Bisesquicentennial, Sestercentennial, Quarter Millennial — good to know because this year on 10 November will be the Marine Corps’ 250th birthday. Although I don’t think I’ll use any of those terms. It’ll simply be USMC 250.

Google searches using each of those terms are unexciting:
USMC Semiquincentennial
USMC Bisesquicentennial
USMC Sestercentennial
USMC Quarter Millennial

And there’s a wiki page for United States Semiquincentennial. Why am I not surprised?

Yea, Quarter Millennial was the first thing that came to my mind.

Can’t we stick to more formal Latin and just call it Semi-D?

Or, to fit the zeitgeist, if a mega-corporation copyrighted CCL that could be the core branding element.

Now I’m wondering how many points I can get in Scrabble with those words.

Those words are quite sesquipedalian.

When my home town celebrated its 150th anniversary, they called it the sesquicentennial, but that’s off by a century from the question posed by the OP.