marrow

¹ American  

[mar-oh] / ˈmær oʊ /

noun

1. Anatomy. a soft, fatty, vascular tissue in the interior cavities of bones that is a major site of blood cell production.

2. the inmost or essential part.

   to pierce to the marrow of a problem.

3. strength or vitality.

   Fear took the marrow out of him.

4. rich and nutritious food.

5. Chiefly British. vegetable marrow.

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marrow ² American  

[mar-oh, mar-uh] / ˈmær oʊ, ˈmær ə /

noun

Scot. and North England.

1. a partner; fellow worker.

2. a spouse; helpmate.

3. a companion; close friend.

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marrow ¹ British  

/ ˈmærəʊ, -rə /

noun

1. dialect a companion, esp a workmate

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marrow ² British  

/ ˈmærəʊ /

noun

1. the fatty network of connective tissue that fills the cavities of bones

2. the vital part; essence

3. vitality

4. rich food

5. short for vegetable marrow

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marrow Scientific  

/ măr′ō /

1. See bone marrow

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marrow Cultural  

1. The soft, specialized connective tissue that fills the cavities of bones. One kind of bone marrow is responsible for manufacturing red blood cells in the body.

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Other Word Forms

• marrowish
  adjective
• marrowless
  adjective
• marrowy
  adjective

Etymology

Origin of marrow¹

First recorded before 900; Middle English marw(e), marwa, Old English mearg, merg; cognate with Dutch merg, German Mark, Old Norse mergr

Origin of marrow²

First recorded in 1400–50; late Middle English marwe, maro(we), “fellow worker, partner,” perhaps from Old Norse margr “many; friendly”

Explanation

The soft stuff inside of a bone is called marrow. Many people cook with marrow from beef bones and consider it a delicacy. Dogs love to gnaw on bones, trying to get at the marrow inside, and many soups and other recipes call for marrow, which is tender and fatty. Human beings, of course, have marrow inside their bones as well, and certain diseases can be treated by marrow transplants. From this biological kind of marrow comes a figurative meaning of marrow — the essence of something. You might say, "This sentence represents the marrow of the novel."

Example Sentences

The drugs targeted rapidly dividing cancer cells in the marrow, but in doing so further damaged an already compromised blood- and immune-making system, often leaving patients defenseless against infection and bleeding.

From The Wall Street Journal • Apr. 19, 2026

Survival, it became clear, depended on whether marrow function could somehow be restored.

From The Wall Street Journal • Apr. 19, 2026

Each year, more than 128,000 people in the United States receive solid organ or bone marrow transplants.

From Science Daily • Apr. 15, 2026

The researchers found no trace of the virus in samples of the man's blood, gut and bone marrow.

From Barron's • Apr. 13, 2026

“Down to the marrow of your bones. I drew you here to serve my purpose. You have eaten at my table, and I have saved your life.”

From "The Name of the Wind" by Patrick Rothfuss