Noun. The practice of divination through dancing in which the dancer, usually a woman, shakes her hips in an up-and-down bouncing motion, causing the dancer's buttocks to shake, "wobble" and "jiggle". A portmanteau of the African American Vernacular English word "twerk" and the Greek, "-manteia" meaning "to prophesy".
Person 1: I can see my future in her shaking buns.
Person 2: Did you just perform an act of twerkomancy?