a character in the novel 1984 by George Orwell. Big Brother is the leader of the state, and although no one has ever met him there are pictures of him everywhere with the message "Big Brother is watching you". People now use the expression 'Big Brother' to describe any government or organization that has complete power, allows no freedom, and carefully watches what people are doing.:
• Increasingly, the state is taking a Big Brother role in this area.
a television programme in which ten people are kept in a house without being able to talk to anyone outside the house. Everything they do is filmed. Each week, the people who watch the show vote by telephone to decide who must leave the house. The last person remaining in the house after ten weeks receives a prize of a large amount of money. The programme has been made and shown in several different countries