Noun, pl. veins
(Anatomy)
1. Blood vessels that carry blood towards the heart. Most veins carry deoxygenated blood from the tissues back to the heart; exceptions are the pulmonary and umbilical veins, both of which carry oxygenated blood to the heart. (wikipedia.org)
2. A blood vessel that transports blood from the capillaries back to the heart. (wiktionary.org)
3. (used in plural veins) The entrails of a shrimp. (wiktionary.org)
(Botany)
1. In leaves, a thickened portion of the leaf containing the vascular bundle (wiktionary.org). One of the vascular bundles or ribs that form the branching framework of conducting and supporting tissues in a leaf or other expanded plant organ. Also called nervure (thefreedictionary.com).
2. A slender rib running through a leaf or bract, typically dividing or branching, and containing a vascular bundle. (Google Dictionary)
(Zoology)
1. The nervure of an insect’s wing (wiktionary.org); One of the horny ribs that stiffen and support the wing of an insect. Also called nervure (thefreedictionary.com).
2. A hardened branching rib that forms part of the supporting framework of a wing, consisting of an extension of the tracheal system; a nervure. (Google Dictionary)
(Geology)
1. A regularly shaped and lengthy occurrence of an ore; a lode (thefreedictionary.com).
Other definitions
1. A fissure, crack, or cleft (thefreedictionary.com).
2. A fracture in rock containing a deposit of minerals or ore and typically having an extensive course underground. (Google Dictionary)
3. A streak or stripe of a different color in wood, marble, cheese, etc. (Google Dictionary)
4. A body of subsurface water, esp. as considered a source or potential source of water for a well or wells and thought of as flowing in a channel. (Google Dictionary)
Word origin: From Old French veine, from Latin vena “a blood vessel,” also “a water course, a vein of metal, a person’s natural ability or interest,” of unknown origin.