CB 
/ˌsi:ˈbi:/ noun
/ˌsi:ˈbi:/ noun [noncount] : a range of radio frequencies that people and especially truck drivers use to talk to each other over short distances often while driving — often used before another noun ▪ a CB radio ; also : a radio that uses this range of frequencies
▪ We heard the truckers talking on the CB. ◊CB is an abbreviation of “citizens band.”
▪ We heard the truckers talking on the CB. ◊CB is an abbreviation of “citizens band.”
