Great saphenous vein
Blood vessels · Latin: Vena saphena magna
The great saphenous vein (GSV, alternately "long saphenous vein";) is a large, subcutaneous, superficial vein of the leg.
It is the longest vein in the body, running along the length of the lower limb, returning blood from the foot, leg and thigh to the deep femoral vein at the femoral triangle.
Definition from Wikipedia, CC BY-SA 4.0.