subcostal vein

noun

: 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