means A loop of rope with a sliding knot that cinches tighter as the standing end is pulled, used for snaring, hanging, or fastening.

from From Middle English nose or nous, likely borrowed from Old French nous or nouse meaning 'knot,' itself from Latin nodus, 'knot' — the same root that ties up our 'node' and 'nodule.' So the noose is, etymologically, just 'a knot,' though history has given that plain little word a far heavier weight than its origins suggest.