chockstone

English

Kjeragbolten, a large chockstone or suspended boulder in Norway.

Climbing nut in use.

Etymology

From chock +‎ stone. The climbing sense derives from the wedges' use as artificial chockstones.

Pronunciation

• (UK) IPA^(key): /ˈtʃɒkstəʊn/

• Audio (Southern England):

  (file)

• (General American) IPA^(key): /ˈt͡ʃɑkstoʊn/

Noun

chockstone (plural chockstones)

1. A stone, ranging in size from a boulder to a pebble, which has become wedged in a vertical fissure or cleft.
   • 2004, Aron Ralston, 127 Hours: Between a Rock and a Hard Place, Simon and Schuster, published 2011, page 68:

     In these coldest hours before dawn, from three until six, I take up my knife again and hack at the chockstone. I continue to make minimal but visible progress in the divot.

2. (climbing) A metal wedge or nut, threaded on a wire, used in rock climbing for protection by wedging it into a crack in the rock.

   Coordinate term: piton

Further reading

• nut (climbing) on Wikipedia.Wikipedia