from The American Heritage® Dictionary of the English Language, 4th Edition
- n. The fine vascular membrane that closely envelops the brain and spinal cord under the arachnoid and the dura mater.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. The inner most of the meninges membranes that surround the brain and spinal cord.
from the GNU version of the Collaborative International Dictionary of English
- The delicate and highly vascular membrane immediately investing the brain and spinal cord.
from The Century Dictionary and Cyclopedia
- The delicate fibrous and very vascular membrane which immediately invests the brain and spinal cord.
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- n. the highly vascular innermost of the 3 meninges
Middle English, from Medieval Latin pia māter : Latin pia, tender + Latin māter, mother (translation of Arabic 'umm raqīqa : 'umm, mother + raqīqa, tender).(American Heritage® Dictionary of the English Language, Fourth Edition)