ˌBig ˈBrothers BrE AmE
a US organization to help boys, especially boys who do not have fathers or who come from families experiencing difficulties. Each boy has his own Big Brother, a man who meets him regularly to give advice, listen to his problems, play games, and be a ↑ role model . Big Brothers are ↑ volunteer s (=people who work without being paid) , and there is a similar organization for girls called ↑ Big Sisters .