Merriam-Webster Collegiate Dictionary - jugular vein

 noun  Date: 1597 any of several veins of each side of the neck that return blood from the head JUGULAR  I. adjective  Etymology: Late Latin ~is, from Latin jugulum collarbone, throat, from jugum yoke — more at yoke  Date: 1597  1. of or relating to the throat or neck  2. of or relating to the ~ vein  II. noun  Date: 1615  1. ~ vein  2. the most vital or vulnerable part of something showed an instinct for the ~ in competition