n :  either of two veins:  a  :  one that arises on the right side of the anterior abdominal wall, follows a course along the lower margin of the twelfth rib, and joins in the formation of the azygos vein - called also right subcostal vein   b  :  one on the left side of the body that usually empties into the hemiazygos vein - called also left subcostal vein  .
 
 
 
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