n. a membrane, especially one of the three membranes enclosing the brain and spinal cord in vertebrates
The Century Dictionary and Cyclopedia
n. In anatomy, a membrane; especially, one of the three membranes that invest the brain and spinal cord.
WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
n. a membrane (one of 3) that envelops the brain and spinal cord
Word Usage
"Each vein of the other pair stretches from the region of the ear to the brain, and branches off in a number of fine and delicate veins into the so-called meninx, or membrane, which surrounds the brain."