1. The largest or most important vein in a particular anatomical region or the body's venous system that carries deoxygenated blood back to the heart
The superior vena cava is one of the principal veins of the human body.
A veia cava superior é uma das veias principais do corpo humano.
2. In mining or geology, the primary or largest vein of ore or mineral deposits
The miners discovered a principal vein of gold in the mountain.
Os mineradores descobriram uma veia principal de ouro na montanha.