phrenic vein

noun

: any of the veins that drain the diaphragm and accompany the phrenic arteries:

a

: one that accompanies the pericardiophrenic artery and usually empties into the internal mammary vein

called also superior phrenic vein

b

: any of two or three veins which follow the course of the inferior phrenic arteries and of which the one on the right empties into the inferior vena cava and the one or two on the left empty into the left renal or suprarenal vein or the inferior vena cava

called also inferior phrenic vein