water knot

Etymology
, apparently. Attested from at least the 18th century.

Noun

 * 1) A type of bend knot used to join the ends of lines or flat material such as tubular webbing.
 * 2) An alternative name for the fisherman's knot, or fisherman's loop
 * 1) An alternative name for the fisherman's knot, or fisherman's loop
 * 1) An alternative name for the fisherman's knot, or fisherman's loop

Usage notes
Commonly employed by mountaineers to create a sling seat, but not considered to be as safe as the beer knot.