root beerBrE/ˈruːt bɪə(r)/NAmE/ˈruːt bɪr/noun[U, C]asweetfizzy drink (= with bubbles), that does not contain alcohol, made from gingerandtherootsofotherplants. ItisdrunkespeciallyintheUS根汁汽水(用姜和其他植物的根制成,不含酒精,盛行于美国)[C]abottle, canorglassofrootbeer一瓶(或听、杯)根汁饮料