vena cava
noun /ˌviːnə ˈkeɪvə/
  /ˌviːnə ˈkeɪvə/
(plural venae cavae 
 (anatomy) /ˌviːniː ˈkeɪviː/
  /ˌviːniː ˈkeɪviː/
)- either of the two veins that take blood without oxygen in it towards the heartWord Originlate 16th cent.: from Latin, literally ‘hollow vein’.