- The definition of a vein is a blood vessel that is part of the circulation system through which blood is carried or a streak of something.
- An example of a vein is what a nurse pricks with a needle when she needs to draw blood.
- An example of a vein is an area in the earth where gold is found.
An illustration showing veins steming from the heart.
vein definition by Webster's New World
- any blood vessel that carries blood from some part of the body back toward the heart
- loosely any blood vessel
- any of the riblike supports strengthening the membranous wings of an insect
- any of the bundles of vascular tissue forming the framework of a leaf blade
- a more or less continuous body of minerals, igneous or sedimentary rock, etc., occupying a fissure or zone, differing in nature from the enclosing rock, and usually deposited from solution by circulating water
- lode (senses 1 & 2)
- a streak or marking of a color or substance different from the surrounding material, as in marble or wood
- any distinctive quality or strain regarded as running through one's character, or a speech, writing, etc.: a vein of humor in the essay
- course or tenor of thought, feeling, action, etc.
- a temporary state of mind; mood: speaking in a serious vein
Origin: Middle English veine ; from Old French ; from Classical Latin vena
- to streak or mark with or as with veins
- to branch out through in the manner of veins
vein definition by American Heritage Dictionary
- a. Anatomy Any of the membranous tubes that form a branching system and carry blood to the heart.b. A blood vessel.
- Botany 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.
- Zoology One of the horny ribs that stiffen and support the wing of an insect. Also called nervure.
- Geology A regularly shaped and lengthy occurrence of an ore; a lode.
- A long wavy strip of a different shade or color, as in wood or marble, or as mold in cheese.
- A fissure, crack, or cleft.
- A pervading character or quality; a streak: “All through the interminable narrative there ran a vein of impressive earnestness” (Mark Twain). See Synonyms at streak.
- a. A transient attitude or mood.b. A particular turn of mind: spoke later in a more serious vein.
- To supply or fill with veins.
- To mark or decorate with veins.
Origin: Middle English veine, from Old French, from Latin vēna.
- veinˈal adjective
vein - Medical Definition
- veinal adjective
vein - Science Definition
- Any of the blood vessels that carry blood toward the heart from the body's cells, tissues, and organs. Veins are thin-walled and contain valves that prevent the backflow of blood. All veins except the pulmonary vein carry blood with low levels of oxygen.
- One of the narrow, usually branching tubes or supporting parts forming the framework of an insect's wing or a leaf. Veins in insect wings carry hemolymph and contain a nerve. Veins in leaves contain vascular tissue, with the xylem usually occurring on the upper side of the vein (bringing in water and nutrients) and the phloem on the lower side (carrying away food). See more at leaf, venation.
- A long, narrow deposit of mineral or rock that fills the void formed by a fracture or fault in another rock. The mineralogy of the host rock surrounding the vein is often altered where it is in contact with the vein because of chemical reactions between the two rock types.
- venous venous adjective