Under what conditions is the word Britisher offensive?
Solution 1:
As per Wiktionary:
Britisher is mainly used in the Indian subcontinent, having become popular there during the British Raj. Its use was once considered pejorative, but is now mostly considered jocular.
This trend of once-offensiveness seems to stem from Britain's colonisation of a sizeable chunk of the world; basically we sailed up to countries and 'claimed' them for Her Majesty and then proceeded to massacre most of the native peoples and to ship in our own population.
In all of this, you had the native people, who tended not to like the invaders, who referred to the British by the common epithet Britisher. Originally not pejorative (indeed used as an autonym) it quickly became so when used by the oppressed.
This was used pejoratively for another 90-odd years, by which time we get to the stage of Britain giving back her colonies, often unceremoniously. By then, negative feeling towards the 'Britishers' was at an all time high, and, as many older people will remember, Britisher was definitely pejorative.
In the following 70 years until now, it has fallen out of use worldwide with a few older people and those from ex-colonial countries still using it.
cf. Ngrams of Britisher