vein

American  

[vayn] / veɪn /

noun

• veins
  plural

1. one of the system of branching vessels or tubes conveying blood from various parts of the body to the heart.

2. (loosely) any blood vessel.

3. one of the riblike thickenings that form the framework of the wing of an insect.

4. one of the strands or bundles of vascular tissue forming the principal framework of a leaf.

5. any body or stratum of ore, coal, etc., clearly separated or defined.

   a rich vein of coal.

6. a body or mass of igneous rock, deposited mineral, or the like occupying a crevice or fissure in rock; lode.

7. a natural channel or watercourse beneath the surface of the earth.

8. the water running through such a channel.

9. a streak or marking, as of a different shade or color, running through marble, wood, etc.

10. a condition, mood, or temper.

    a vein of pessimism.

11. a tendency, quality, or strain traceable in character, conduct, writing, etc.; manner or style.

    to write in a poetic vein.

    Synonyms:

    thread, hint, touch, streak, tone

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verb (used with object)

1. to furnish with veins.

2. to mark with lines or streaks suggesting veins.

3. to extend over or through in the manner of veins.

   Broad new highways vein the countryside.

vein British  

/ veɪn /

noun

1. any of the tubular vessels that convey oxygen-depleted blood to the heart Compare pulmonary vein artery

2. any of the hollow branching tubes that form the supporting framework of an insect's wing

3. any of the vascular strands of a leaf

4. a clearly defined mass of ore, mineral, etc, filling a fault or fracture, often with a tabular or sheetlike shape

5. an irregular streak of colour or alien substance in marble, wood, or other material

6. a natural underground watercourse

7. a crack or fissure

8. a distinctive trait or quality in speech, writing, character, etc; strain

   a vein of humour

9. a temporary disposition, attitude, or temper; mood

   the debate entered a frivolous vein

10. a parting in hair

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verb

1. to diffuse over or cause to diffuse over in streaked patterns

2. to fill, furnish, or mark with or as if with veins

vein Scientific  

/ vān /

1. 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.

2. 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).

3. See more at leaf venation

4. 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.

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Other Word Forms

Derived Forms

• subvein
  noun
• intervein
  verb (used with object)
• interveinal
  adjective
• unveined
  adjective
• veinal
  adjective
• veinless
  adjective
• veinlike
  adjective
• veiny
  adjective

Inflected Forms

Nouns

• veins
  plural

Etymology

Origin of vein

1250–1300; Middle English veine < Old French < Latin vēna vein of the body, channel, ore deposit

Explanation

A vein is a blood vessel. If you've ever donated blood, you know that having a needle put in your vein by a health care worker is not nearly as scary as it sounds. Although it mainly describes part of the body's circulatory system, vein can also refer to a pattern that looks like a vein in your body. For example, you can describe the streaks of color that run through blue cheese as veins of greenish-blue. Similarly, a theme or idea that continues appearing throughout a book could be called a vein. The trickiest thing about the word vein is trying not to confuse it with its homophones — vane (as in weather vane) and vain (as in conceited).

Example Sentences

See Examples For:

vein veins

Pike, he said, had helped the execution team find a vein in her arm, and she was kind and polite while she was being injected.

From BBC ● Oct. 7, 2026

One possibility, a huge possibility, is that the catheter became dislodged from her vein and then was spilling the drugs into the surrounding tissue.

From Slate ● Oct. 6, 2026

How did you see a Southern California vein begin to appear in punk?

From Los Angeles Times ● Sep. 24, 2026

After the longest wait between albums of his career, “Ride Lonesome” is his third record in this reflective vein, which means it’ll be a stark contrast to his electro-streaked 2019 LP, “Hyperspace.”

From The Wall Street Journal ● Sep. 9, 2026

"She got so mad, I thought a vein would pop right out of her neck."

From "The Belles" by Dhonielle Clayton

Pike's legal team had previously objected to the execution IV protocol, saying it would have caused needless suffering due to her small veins and a blood condition.

From Barron's ● Oct. 10, 2026

Pike's medical condition of thrombocytosis may have also played a role, forming blood clots at the injection site that would potentially block pentobarbital from entering her veins.

From BBC ● Oct. 2, 2026

These veins contain minerals including calcium sulfate and fluorite.

From Science Daily ● Sep. 30, 2026

They called the court’s attention to Pike’s “individual physical characteristics that include, but are not limited to, Thrombocytopenia/Thrombocytosis, Bipolar disorder, Post Traumatic Stress Disorder, hyperlipidemia, and small veins that make insertion of a needle difficult.”

From Slate ● Aug. 25, 2026

His hands were clenched in fists, his face was red, and you could just about see the blood running, fast, through the big veins sticking out on his arms and the sides of his head.

From "Ida B" by Katherine Hannigan

Related Words

• hair
• lode
• nerve
• seam
• stripe