Twilight Rappel from the Eaglet Spire,
Franconia Notch, NH
I rappel, not repel! The words are easily mixed up and the misuse of Repel in place of Rappel is especially common.
Rappel
To descend a vertical surface, especially a cliff face, by sliding down a rope with a device that provides friction.
Repel
1. to ward off or drive back
2. to cause aversion or distaste
3. to present an opposing force