资料来源 : Webster's Revised Unabridged Dictionary (1913)

Subdural \Sub*du"ral\, a. (Anat.)
   Situated under the dura mater, or between the dura mater and
   the arachnoid membrane.

资料来源 : WordNet®

subdural
     adj : below the dura mater but above the arachnoid membrane of the
           meninges