"Mean" is another word that the Americans seem to use differently. In the British Isles it's more likely to be about someone who is tight fisted, rather than hostile, or nasty (and sometimes seen as somewhat admirable for that).

Of course the American usage is understood and often enough used, but I think that's mostly because we're deluged by American movies and television from our childhood.
We don't need subtitles to follow even the weirdest American accents.

It's interesting how often the accent that journalists and such from other countries have acquired isn't English or American, it's Irish.