One of the biggest English language variations is the Irish and English meaning of the word 'bugger'. In Irish vernacular it means rascal or scamp; 'wee bugger' is a common Northern Irish term.
It uh, means something different in the rest of the UK; a mild swear word or something else.
My American cousins were shocked when I told them. 🤣
This ad caused issues, but is probably more famous here now that it did.