A term I first heard and have since used in the movie Miller's Crossing. The high hat means to diss, insult, and ignore in a sense. You give someone the high hat, I'm sure the term comes from a gesture involving a hat. Miller's Crossing takes place in the 30's, and the Coen Brothers pay close attention to dialogue in their movies. Although I don't wear hats, I don't hesitate to inform people they have been given the the high hat by a date or friend. Obviously, I don't own a collection of hats from the high hats I have received in my life. But most of the time, I remember why.

"Take your flunky and dangle.........."