Abseiling rappelling in American English, is the controlled descent down a rock face using a rope; climbers

Climbing

Climbing is the activity of using one's hands and feet to ascend a steep object. It is done both for recreation and professionally, as part of activities such as maintenance of a structure, or military operations.Climbing activities include:* Bouldering: Ascending boulders or small...

 use this technique when a cliff or slope is too steep and/or dangerous to descend without protection.
Slang terms for the technique include: rapping or rap jumping (American slang), deepelling (Canadian slang), abbing (British slang

British slang

British slang is English language slang used in the UK. Slang is informal language sometimes peculiar to a particular social class or group and its use in Britain dates back to before the 16th century...

 for "abseiling"), rappling (Hindi

Hindi

Standard Hindi, or more precisely Modern Standard Hindi, also known as Manak Hindi , High Hindi, Nagari Hindi, and Literary Hindi, is a standardized and sanskritized register of the Hindustani language derived from the Khariboli dialect of Delhi...

 slang).
The term rappel / rappelling is derived from the French language: French, recall, return, rappel, from Old French, recall, from rappeler, to recall: re-, re- + appeler, to summon.
The origin of the abseil is attributed to Jean Estéril Charlet, a Chamonix

Chamonix

Chamonix-Mont-Blanc or, more commonly, Chamonix is a commune in the Haute-Savoie département in the Rhône-Alpes region in south-eastern France. It was the site of the 1924 Winter Olympics, the first Winter Olympics...

 guide who lived from 1840–1925.