Marrow is defined as an innermost, choice part, especially the fatty tissue inside bones.(noun)
An example of marrow is the substance in bones that can be donated to a sick person in need of a blood marrow transfusion.
See marrow in Webster's New World College Dictionary
Origin: ME merow < OE mearg, akin to Ger mark, marrow < IE base *mozgho-, marrow, brains > Sans majján-, marrow
See marrow in American Heritage Dictionary 4
Origin: Middle English marow
Origin: , from Old English mearg.
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