Blighty is a warm, old nickname for Britain — not the official name on a map, more like saying “home.” British soldiers and other British people working far away for the British Empire used it a lot in the 1800s and early 1900s. If you were in India, or in a trench, and you longed for Blighty, you longed for Britain. People still use it now and then, but mostly with a smile, in old songs, or when someone is playing at being an old soldier. A young person in London today would not say it with a straight face. It is very British; Americans do not use this word. Though actually, it did not start as an English word for home. In India, vilāyatī meant “foreign” — often the foreign things the British had brought, such as tomatoes (called “foreign aubergine”) and soda water. British soldiers took that sound, wore it down into Blighty, and used it for Britain itself. So a word that meant “from abroad” became a loving name for home. Soldiers also talked about “a Blighty one”: a wound just bad enough to send you home, which tells you how strongly the word meant “Britain, at last.”

英國（舊時英軍對祖國的暱稱）