big brother

noun

1. an elder brother.
2. (sometimes initial capital letters) a man who individually or as a member of an organized group undertakes to sponsor or assist a boy in need of help or guidance.
3. (usually initial capital letters) the head of a totalitarian regime that keeps its citizens under close surveillance.
4. (usually initial capital letters) the aggregate of officials and policy makers of a powerful and pervasive state.
5. Citizens Band Radio Slang. a police officer or police car.

noun

1. a person, organization, etc, that exercises total dictatorial control
2. a television gameshow format in which a small number of people living in accommodation sealed off from the outside world are constantly monitored by TV cameras. Viewers vote each week to expel a person from the group until there is only one person left, who wins a cash prize