https://www.dictionary.com/browse/augur-well-for
I was watching a British show ("Coronation Street") and the word "augur" was used twice. I wonder how many Americans would know it means? Few I think.
I was watching some other show where the word "peripatetic" was said. I doubt if 1 American in a 100 would know what it meant.
https://en.wiktionary.org/wiki/peripatetic
I once referred to a female friend's boyfriend as her "beau". She asked me what it meant.