The term RELATING TO BONE MARROW can be summarized by two crossword solutions: MYELOID (7 letters) and MEDULLARY (9 letters). Myeloid refers to the type of tissue that makes up the bone marrow, which is responsible for producing red and white blood cells. Medullary refers to the innermost layer of the bone marrow, which is composed of fat cells and hematopoietic stem cells. Both terms are related to the bone marrow, which is a spongy tissue found in the center of most bones.