English is the common language in the USA, the U.K., Ireland and many other countries; but that doesn’t mean English, especially “slang” English is the same everywhere. Even in English speaking countries, Americans should be careful about the words they use.
If you want to avoid being an “Ugly American”, don’t use these words in certain countries:
Pants: In the U.K. and Ireland “pants” means “underwear”. When shopping or referring to someone’s clothing, use “trousers” instead.
Fanny: In the U.K., Ireland, Australia, New Zealand and South Africa, “Fanny Packs” are called “bum bags”. And “Fanny” in those countries is also slang for a part of female anatomy, but not the rear portion.
Pissed: A word generally associated with urination but with many other meanings as well. Americans use “pissed” as an expression of anger, but in Britain and Ireland, someone who is “pissed” is extremely intoxicated. “Taking the (or a) piss” in those countries, however, means “to make fun of”.
Bangs: Americans call that fringe of hair over the forehead “bangs”, is also called a “fringe” in other countries. However, the expression “he (or she) bangs”, has the same meaning in other nations as well.
Knob: Americans will think of a door “ knob” or perhaps a reference to the head. But in Australia and the U.K., it’s slang for a unique part of the male anatomy. If you’re called a “Knob Head” there, it’s the same as being called a “Dick Head” in the USA.
Bugger: You may affectionately call a pet or an infant a “little bugger”, but in many other English speaking countries, it’s the expletive equivalent to the “F-word”.