teaser
From Longman Dictionary of Contemporary Englishteaserteas‧er /ˈtiːzə $ -ər/ noun [countable] informal 1 ASK A QUESTIONa very difficult question that you have to answer as part of a game or competition2 a short advertisement which appears a few days or weeks before a full advertisement for a productExamples from the Corpusteaser• How New Ways With Eyeshadow turn a housewife to a teaser.• Why bother with the blond teasers?• Add Bolo 2 to your collection of brain teasers and give your brain a good work out.• I rarely find much satisfaction in debating harder abstractions or metaphysical teasers with him.From Longman Business Dictionaryteaserteas‧er /ˈtiːzə-ər/ noun [countable]MARKETING an advertisement intended to get people’s attention for advertisements that will come later or products that will be available laterThe teasers urged viewers to tune in at a specific time to watch the launch of the company’s advertising campaign.