teas·er 
(tēzər)
(tēzər)n.
1.
a. One that teases, as a device for teasing wool.
b. One who engages in teasing; a tease.
2. A puzzling problem.
3. An advertisement that attracts customers by offering something extra or free.
4. Slang An attention-getting vignette or highlight, as one presented before the start of a television show.