red marrow vs bone marrow

red marrow and bone marrow both are nouns.

Word	Noun	Adjective	Verb	Adverb
red marrow	Yes	No	No	No
bone marrow	Yes	No	No	No

As nouns, bone marrow is a hypernym of red marrow; that is, bone marrow is a word with a broader meaning than red marrow:

red marrow: bone marrow of children and some adult bones that is required for the formation of red blood cells
bone marrow: the fatty network of connective tissue that fills the cavities of bones

Other hypernyms of red marrow include marrow.

red marrow (noun)	bone marrow (noun)
bone marrow of children and some adult bones that is required for the formation of red blood cells	the fatty network of connective tissue that fills the cavities of bones
	very tender and very nutritious tissue from marrowbones