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

See Examples For:

marrow

Despite a battery of tests, including a contrast CT scan and bone marrow biopsy, experts could not determine what was making Jackie critically ill.

From Los Angeles Times ● Aug. 10, 2026

Eksteen said a recent contrast CT scan and bone marrow biopsy “have provided our veterinary team with important new information” but added the picture remains incomplete.

From Los Angeles Times ● Aug. 8, 2026

Those cells are hematopoietic cells, meaning they are blood cells produced in bone marrow.

From Science Daily ● Aug. 5, 2026

In these cases, doctors may diagnose cancer largely by examining the appearance of cells in the bone marrow.

From Science Daily ● Aug. 1, 2026

Finny had a vitality which could not be quenched so suddenly, even by the marrow of his bone.

From "A Separate Peace" by John Knowles