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English definition of “arachnoid”

arachnoid

noun [C] /əˈræk.nɔɪd/ US  /əˈræk.nɔɪd/ specialized
the delicate covering of the brain or spinal cord: Symptoms associated with an arachnoid cyst can include headaches, nausea, seizures, and visual disturbances.The brain and nervous system
(Definition of arachnoid noun from the Cambridge Advanced Learner's Dictionary & Thesaurus © Cambridge University Press)

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