名詞 teaser:

1. a worker who teases wool
2. someone given to teasing (as by mocking or stirring curiosity)
   同義詞：tease, annoyer, vexer
3. an advertisement that offers something free in order to arouse customers' interest
4. a particularly baffling problem that is said to have a correct solution
   同義詞：puzzle, puzzler, mystifier
5. an attention-getting opening presented at the start of a television show
6. a flat at each side of the stage to prevent the audience from seeing into the wings
   同義詞：tormenter, tormentor
7. a device for teasing wool

1. This one's a real teaser.
   這可真是個難題。