teas·er /ˈtiːzə $ -ər/ noun [countableC] informal 1. ASK A QUESTIONa very difficult question that you have to answer as part of a game or competition 〔游戏或竞赛中的〕难题
2. a short advertisement which appears a few days or weeks before a full advertisement for a product 前导广告,预热广告