What does "vein" mean?

Additional senses

1. 2.(Zoöl.) One of the ribs or nervures of the wings of insects. See Venation.
2. 3.(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.
3. 4.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.
4. 5.A streak or wave of different color, appearing in wood, and in marble and other stones; variegation.
5. 6.A train of association, thoughts, emotions, or the like; a current; a course. He can open a vein of true and noble thinking. Swift.
6. 7.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.
7. 8.To form or mark with veins; to fill or cover with veins. Tennyson.