nerfherder
Adventurer
"Unamerican" is a word I see a lot on social media, at least weekly. How many countries have "un-[nationality]" as an insult? I've never heard anyone use the phrase "un-British", I don't think. Do the French say "un-French"? The Russians? The Japanese? Is a national character a common thing?
I think the nearest I've heard is "that's not cricket" - with the implication that the English are honest, moral, and sporting (and that being more important than winning).