- 1any of the tubes forming part of the blood circulation system of the body, carrying mainly oxygen-depleted blood towards the heart. Compare with artery.
Middle English: from Old French veine, from Latin vena. The earliest senses were 'blood vessel' and 'small natural underground channel of water'
Do not confuse vain with vane or vein. Vain means 'having a very high opinion of yourself' (a vain woman with a touch of snobbery) or 'without success or a result' (a vain attempt to tidy up); vein means 'a tube that carries blood around the body' or 'a particular style or quality' (he continued in a more serious vein); vane means 'a broad blade forming part of a windmill, propeller, or turbine'.