medullary substance

n.

The fatty material present in the myelin sheath of nerve fibers.
medulla

Words nearby medullary substance

medullary sheath, medullary space, medullary sponge kidney, medullary stria of fourth ventricle, medullary stria of thalamus, medullary substance, medullated, medullated fiber, medullation, medullectomy, medullization