1Chiefly in skating, snowboarding, etc.: any of various turns or manoeuvres executed by shifting the weight on to the heel or heels.
2In ballroom dancing: a movement in which a dancer steps backwards, transferring his or her weight to the back heel, on which he or she then pivots.
While the dancer turns on the back heel, he or she draws the free foot back to meet the supporting one, and finally transfers the weight from the supporting foot to the closing one, ready for the next step.
3The action or an instance of turning round sharply, especially so as to face in the opposite direction. Also figurative: a complete change of attitude or opinion.
An instance of a wrestler who has been cast as a hero undergoing a character shift and adopting the persona of a villain, typically in a sudden, shocking move. Later, in extended use: any instance of a sudden shift from hero to villain.
Late 19th century; earliest use found in Henley's Manual Roller Skating. From heel + turn.