Dunckle is a slang term that originated in Ulster County, NY. Dunckle means pulling a fast one on someone. To pull the wool over ones eyes and take advantage of another person with no remorse. This is usually done to a white female by her male black lover. To extort money out of someone by stealing, telling lies to and or ultimately scamming them.
Man, that guy pulled a dunckle on me.
I can't believe he dunckled her like that!