vena ca·va 
(kāvə)
(kāvə)n. pl. venae ca·vae (kāvē)
Either of two large veins that drain blood from the upper body and from the lower body and empty into the right atrium of the heart.
[New Latin vēna cava : Latin vēna, vein + Latin cava, hollow.]
vena caval (-vəl) adj.