Coined by my friend Bonnie-Ann Black: bi-English.
As in, fluent in both American English and British English.
The Brits in London -- where Bonnie and I are traveling at the moment -- seem to find it amusing when we explain that they don't need to adjust their slang, because we're "bi-English."
(word of the day/phrase of the day: I highlight a word or phrase, especially new coinages or clever usages, that tickles me)




Tri-English: absolutely. But you'd need more than a smattering to be considered fluent.
I agree with the sitcom thing, but it's actually quite a different thing to hear the language in the real world... and it's also fun to watch the reactions of some Brits when they hear British English with an American accent!