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bone marrow

American  

noun

  1. marrow.

bone marrow British  

noun

  1. See marrow 1

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
bone marrow Scientific  

  1. The spongy, red tissue that fills the bone cavities of mammals. Bone marrow is the source of red blood cells, platelets, and most white blood cells.

bone marrow Cultural  

  1. See marrow.

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

Bone marrow contains several specialized microenvironments known as "niches."

From Science Daily • Nov. 20, 2025

Bone marrow transplants between mice can transmit symptoms and pathology associated with Alzheimer’s disease, according to a controversial study published today in Stem Cell Reports.

From Science Magazine • Mar. 28, 2024

Bone marrow transplants also carry significant risk and have been used only on HIV patients who have developed cancer.

From Washington Post • Jul. 27, 2022

Bone marrow is the soft, spongy tissue found at the centre of certain bones in the body where blood stem cells live.

From BBC • Jun. 30, 2022

Bone marrow as an index of malnutrition in deer.

From An Experimental Translocation of the Eastern Timber Wolf by Hook, Richard A.

Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.