'piton' definitions:

Definition of 'piton'

noun

A metal spike with a hole for a rope; mountaineers drive it into ice or rock to use as a hold

From: GCIDE

piton \pi"ton\ (p[=e]"t[o^]n), n. (Mountain Climbing) A metal spike having a sharpened point on one end, and a hole through which a rope can be passed on the other; it is driven into the face of a rock cliff during climbing, and used as an anchor point for a rope. [PJC]