subarachnoid

/ˌsʌbəˈræknɔɪd/
adjective
  1. Relating to the space or region beneath the arachnoid membrane of the brain and spinal cord, which contains cerebrospinal fluid.
    • Doctors use a lumbar puncture to sample fluid from the subarachnoid region.
    • A subarachnoid hemorrhage is a medical emergency caused by bleeding in the brain.
    • The subarachnoid space cushions the brain with fluid.
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