adj.
Situated or occurring beneath the arachnoid membrane, or between the arachnoid and the pia mater: subarachnoid space; subarachnoid anesthesia.
The American Heritage® Dictionary of the English Language, Fourth Edition Copyright © 2007, 2000 by Houghton Mifflin Company. Updated in 2009. Published by Houghton Mifflin Company. All rights reserved.
