- a vein accompanying another structure; a vein may accompany an artery in such a way that the arterial pulses aid venous return
- accompanying vein of hypoglossal nerve
- There is a vein of melancholy in his character.
- She helps her mother when she is in the vein.
- A vein of gold was seen cropping out.
- The central or principal vein of a leaf.
- He had no comedy vein in his youth.