Just to add a little to Obo's fine answer, 'bilayati' - based on Arabic originally - is actually an adjective meaning 'foreign' or more specifically 'European' in the Hindi language. ('Bilayati pani' - European water - for example was what the natives called soda-water, which the sahibs would have in their whiskies.) Strangely enough, despite the centuries of earlier association between British soldiers etc with India, the word in the form 'blighty', meaning 'England/home' did not - as Obo has already said - become common until World War I.