Definitions for "Subarachnoid"
Situated under the arachnoid membrane.
Literally, beneath the arachnoid, the middle of three membranes that cover the central nervous system. In practice, subarachnoid usually refers to the space between the arachnoid and the pia mater, the innermost membrane surrounding the central nervous system. See the entire definition of Subarachnoid
Located under the arachnoid membrane and above the pia mater.