Grinding, also known as freak dancing or freaking (in the Caribbean, whining, is a type of close partner dance where two or more dancers rub or bump their bodies against each other, especially a female dancer rubbing her buttocks against a male dancer’s crotch area, in imitation of rear-entry or “doggie style” practiced in sexual activity.

Grinding gained widespread popularity as a hip hop dance and a Jamaican dancehall dance in night clubs, and eventually moved on to high school and middle school dances especially in the US and Canada where there have been cases of administrators attempting to ban it due to its explicit over exaggerated pornographic nature.

A predecessor to grinding as a sexually charged high-contact social dance was “The Bump”, popular in the 1970s, in which the contact between partners generally involved the hips or buttocks of one dancer “bumping” those of the other dancer in temporary contact. 

Other predecessor elements of grinding may be attributed to the 1987 film Dirty Dancing, and the lambada, a brief dance craze of the 1980s that featured grinding actions, as seen in the films The Forbidden Dance and Lambada. 
A more explicit and vulgar form of the dance is known as daggering.