grey matter
noun [ U ] (US usually gray matter) uk/ˈɡreɪ ˌmæt.ər/ us/ˈɡreɪ ˌmæt̬.ɚ/
anatomy specialized（大脑和脊髓中的）灰质
the darker tissue containing nerve fibres (= structures like threads) found in the brain and spinal cord
Compare: white matter
informal头脑，智力
a person's intelligence
It's not the sort of film that stimulates the grey matter much. 这部片子不是那种发人深思的电影。