Short for Cock Tease. Plural: CT's or Cock Teases. A woman that screws with your mind by getting you sexually aroused (eg. grinding againt you) and then rejecting you when you want to take it further. Can result in a case of blue balls if severe enough.
Man 1: Dude, this chick was all over me then totally bailed when I wanted head!
Man 2: Damn CT's man.