guest beer
noun
1- Brit. (in a tied public house) a beer offered in addition to those produced by the brewery〈英〉（特约经销某一牌子啤酒的酒吧供应的）其他牌子的啤酒
1.1
- (in a free house) a beer available only temporarily（出售各种牌子啤酒的酒吧）临时供应的某种啤酒。