- noun a thin tube that forms part of the structure of a leaf or the circulation system of an animal, allowing the flow of liquids
- A thin layer or deposit of one material in another, usually in an approximate plane.
- noun a blood vessel that takes deoxygenated blood containing waste carbon dioxide from the tissues back to the heart
Origin & History of “vein”
Vein comes via Old French veine from Latin vēna ‘blood vessel’, a word of uncertain origin. Acquired directly from Latin were the derivatives venose (17th c.) and venous (17th c.).