Slide Vertically Down a Rock Face on a Rope
Puzzle 14 of The Moon Hard Pack
Question is: Slide Vertically Down a Rock Face on a Rope
and the answer is: ABSEIL
Word Meaning:
ABSEIL — (intransitive) To descend a steep or vertical drop using a rope with a mechanical friction device or (classic abseil) by wrapping the rope around the body.
Definitions from Wiktionary.