i Register
In some senses, britisher is marked as US, rare. Watch for register when choosing this word.
noun
A Briton.
"Why now, I expect," said the American, "you would not shoot me in cold blood, although you are a Britisher, I guess."
[…] and as he spoke, there was just a soupçon of foreign accent in the pronunciation of the French vowels, a certain drawl of o's and a's, that would have betrayed the Britisher to an observant ear.
The British colonial authorities; a European member of the British Raj, especially an officer from the colonial authorities.
adj
British
'Thought you'd like to hear some Britisher music. What you'd like. Some Beatles or some Rolling Stones maybe? They're Britisher, OK?'