When you were in elementary school, you probably got teased. Maybe you even teased a few people yourself, especially if you have younger siblings. However, as you got older, you probably heard the word "tease" more often in a different sense...
The word "tease" has a literal meaning of "to pull or scratch"--as in teasing your hair (which was much more popular in the '80s than it is today). The figurative meaning of "to provoke or annoy" developed in the 1600s from the Old English word taesan, which meant to pluck or pull apart.
Today, the word "tease" is used as an insult to describe a person (generally a female or gay male) who flirts and behaves in an overtly sexual manner in order to get the attention of (usually) men, but without the intention to follow through with sex. This usage has been around since the 1970s as a shortened version of the term "cock-tease"--which is why the term tease is not typically used to describe heterosexual men.
Being a tease is not the same as being a flirt. Unlike flirting (which is lighter and less serious), teasing (in this sense) is seen as being purposefully misleading and sometimes, intentionally hurtful. A tease knows what she is doing and supposedly receives pleasure or a feeling of power from her actions.
A common movie character is the girl who is wrongly accused of being a tease. She is usually a good girl with a nasty ex-boyfriend who became angry when she wouldn't have sex with him. One especially famous version of this character is Claire (Molly Ringwald) in "The Breakfast Club."
The sexually frustrated male who calls his ex-girlfriend a tease is such a frequently used character that it was even spoofed in "Not Another Teen Movie," in which the main character, Jake, announces: "...Maybe you should get on that plane to Paris. 'Cause if you stay, we really only have the summer, then I go to college and we'll talk on the phone and spend the occasional weekend together, which is nice. But chances are, one night I'm gonna get wrecked and have unprotected sex with some girl in my dorm. You'll find her thong and call me a slut...I'll call you a cock-tease and we'll break up. So when you really think about it, what's the point?"
