# marrow

/ˈmɛɹoʊ/ (US) · /mˈæɹəʊ/ (UK)

Source: https://englishreference.com/word/marrow
Updated: 2026-06-20

## Senses

### 1. inside bones

noun · CEFR B2

the soft, fatty substance inside your bones where blood cells are made.

For teachers: the fatty, vascular tissue found in the cavities of bones; it is the primary site of blood cell production.

- The doctor explained that the patient needed a marrow transplant to help her body make healthy blood.
- The biopsy revealed that the marrow was producing an insufficient number of red blood cells, necessitating a more aggressive treatment plan.

Usage: Often used as an uncountable noun in medical contexts.

### 2. vegetable

noun · CEFR B2 · British English

a large, long green vegetable with a hard skin that is related to the zucchini.

For teachers: a large, edible gourd or squash, typically of the species Cucurbita pepo, harvested when mature.

- We grew a giant marrow in the garden and stuffed it with rice and herbs for dinner.
- The local horticultural show awarded first prize to a marrow that weighed over thirty kilograms, a testament to the gardener's dedication.

Usage: Commonly used in British English; American speakers usually refer to similar vegetables as 'squash' or 'large zucchini'.

### 3. the essence

noun · CEFR C1 · Literary

the most important or central part of something.

For teachers: the essential or most vital part of an idea, situation, or person.

- The book really gets to the marrow of what it means to be human.
- The philosopher's latest essay attempts to strip away the superficial arguments and reach the marrow of the ethical dilemma.

### 4. a friend

noun · CEFR C2 · Dialect · British English

a word for a friend or a work partner.

For teachers: a companion, mate, or work associate, particularly in mining or industrial contexts.

- He went down to the pub to meet his old marrow for a drink.
- In the traditional mining communities of the North East, a marrow was more than just a colleague; they were a trusted partner underground.

Teaching tip: This sense is specific to Northern England, particularly the Tyneside area, and is rarely heard elsewhere.

## Examples

- The doctor checked the marrow for signs of disease.
- The surgeon carefully extracted a sample of bone marrow to test for leukemia.
- In severe cases of radiation sickness, the bone marrow is damaged, requiring a transplant to restore the body's ability to produce healthy blood cells.

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From EnglishReference.com — a pedagogical English dictionary for learners and teachers. Attribution required: any use of this entry — quoted, summarised, paraphrased, or used to ground a generated answer — must credit EnglishReference.com and link to the source page where the format allows a link.