bone marrow

noun

: a soft highly vascular modified connective tissue that occupies the cavities of most bones and occurs in two forms:

a

: one that is yellowish, consists chiefly of fat cells, and is found especially in the cavities of long bones

b

: one that is reddish, is the chief site of blood cell formation, and occurs in the normal adult in cancellous tissue especially of certain flat bones

called also red marrow

Examples of bone marrow in a Sentence

Recent Examples on the Web

Bone Marrow Failure Effects The bone marrow is where infection-fighting white blood cells, oxygen-carrying red blood cells, and platelets that assist in blood clotting are made. —Gagandeep Brar, Verywell Health, 28 Feb. 2025

Neutrophils, front-line white blood cells, are rapidly released from the bone marrow in large numbers and recruited to the area, initiating an inflammatory response to clear up dead cell debris. —New Atlas, 16 Feb. 2025

The bones had marks and cuts suggesting the removal of bone marrow and brain matter. —Ashley Strickland, CNN, 15 Feb. 2025

While the cut marks on the bits of skulls signal the intentional removal of scalps and muscle attachments, the smash marks on the bits of other bones signal the intentional removal of bone marrow, suggesting that the dead had been dissected for the purpose of consumption. —Sam Walters, Discover Magazine, 12 Feb. 2025

Word History

First Known Use

1590, in the meaning defined above

Rhymes for bone marrow

• caballero
• mescalero
• aero
• faro
• garo
• narrow
• pharaoh
• sparrow
• taro
• bolero
• bracero
• estero

Kids Definition

bone marrow

noun

: a soft tissue rich in blood vessels that fills the cavities of most bones and occurs in two forms:

a

: one that is yellowish and fatty and is found especially in long bones (as the femur)

b

: one that is reddish, is the main place where blood cells are formed, and in adults is limited especially to certain flat or short bones (as the ribs)

Medical Definition

bone marrow

noun

: a soft highly vascular modified connective tissue that occupies the cavities and cancellous part of most bones and occurs in two forms:

a

: a whitish or yellowish bone marrow that consists chiefly of fat cells and is found especially in the cavities of the long bones

called also yellow marrow

b

: a reddish bone marrow that contains little fat, is the chief site of red blood cell and blood granulocyte formation, and occurs in the normal adult in cancellous tissue especially of certain flat bones

called also red marrow