A slumdog is a very poor person, usually a child or young person, who grows up in a slum — the crowded, badly built part of a city where the poorest people live. This is a young word, and an unusual one: most people first met it in the title of the 2008 film Slumdog Millionaire, about a boy from a Mumbai slum who wins a TV quiz show. Before that film it was barely used. It is not a neutral word. Built from 'slum' plus 'dog', it carries the insult of calling a human being a street dog — something dirty, unwanted, living off scraps. When the film came out, many people in India objected to it for exactly this reason. So you should treat it as an offensive word for a real person. Where you WILL see it used is in a kind of reversed way — a person from a slum using it about themselves, proudly, the way people sometimes take an insult thrown at them and wear it. That move works when it is your own word about your own life; it does not work when an outsider says it. For your English, the safe and normal way to say this is 'someone from the slums' or 'a kid who grew up in a slum'. Know 'slumdog' so you understand the film title and the news stories around it — that is the honest reason to learn it.

貧民窟出身的窮人(帶侮辱意味);多半是因為電影《貧民百萬富翁》才聽過這個字