ˈpīəˈmād.ə(r), -ātə- noun
Etymology: Middle English, from Medieval Latin, from Latin, tender mother
: the delicate and highly vascular membrane of connective tissue investing the brain and spinal cord, lying internal to the arachnoid and dura mater, dipping down between the convolutions of the brain, and sending an ingrowth into the anterior fissure of the cord