One of the vessels which carry blood, either venous or arterial, to the heart. See Artery, 2.
- Anatomy Any of the membranous tubes that form a branching system and carry blood to the heart.
- 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 transient attitude or mood.
- A particular turn of mind: spoke later in a more serious vein.
- To supply or fill with veins.
- To mark or decorate with veins.