Going back a few years to the comments about "bathroom" being a euphemism for "lavatory" - it wasn't when I was in New Zealand, and wouldn't have made sense. NZ houses generally had a separate roomlet for the toilet, with a separate entrance from the bathroom. "Bathroom" meant a toom with a bath in it. (This may have been reinforced by Maori concepts of hygiene, which prohibit washing and shitting in the same place).

My pet hate Americanism is biscuits in the UK being sold as "cookies". British cuisine doesn't HAVE cookies. They belong to an alien taxonomy of foods.