noun
arachnoid mater; arachnoid membrane
Anatomical term for the middle layer of the meninges surrounding the brain and spinal cord.
くも膜は脳を保護する三層の膜の一つです。
The arachnoid mater is one of the three layers of membrane that protect the brain.
くも膜下出血
A subarachnoid hemorrhage requires emergency treatment.
From くも (spider) + 膜 (membrane), calque of New Latin 'arachnoidea mater', so named because of its web-like appearance.