What is the 'Coin-of-the-Realm'?

Question

I ordered a privately-minted non-circulating legal tender 'Coin-Certificate payable in coin-of-the-realm' and am wondering what the term coin-of-the-realm means. This is in the USA if that has any matter on this.

Thanks!

Answer 1

In the American Revolutionary time, it referred to coins of Great Britian or other coins that circulated on par with them, but now there are a number of countries that use the term to refer to their own "realm".