1. One of the vessels which carry blood, either venous or arterial, to the heart. See Artery, 2.
2. (Bot.) One of the similar branches of the framework of a leaf.
3. (Zoöl.) One of the ribs or nervures of the wings of insects. See Venation.
4. (Geol. or Mining) A narrow mass of rock intersecting other rocks, and filling inclined or vertical fissures not corresponding with the stratification; a lode; a dike; -- often limited, in the language of miners, to a mineral vein or lode, that is, to a vein which contains useful minerals or ores.
5. A fissure, cleft, or cavity, as in the earth or other substance. "Down to the veins of earth." Milton.
"Let the glass of the prisms be free from veins." -- Sir I. Newton.
6. A streak or wave of different color, appearing in wood, and in marble and other stones; variegation.
7. A train of association, thoughts, emotions, or the like; a current; a course.
"He can open a vein of true and noble thinking." -- Swift.
8. Peculiar temper or temperament; tendency or turn of mind; a particular disposition or cast of genius; humor; strain; quality; also, manner of speech or action; as, a rich vein of humor; a satirical vein. Shak.
"Certain discoursing wits which are of the same veins." -- Bacon.
"Invoke the Muses, and improve my vein." -- Waller.