smooth-brained

adjective3

1. •
   Having a brain which is naturally smooth in appearance.
2. •
   (slang, offensive) Stupid, foolish; ignorant.

   • Although the pandemic might halt the production of these reality shows for the time being, smooth-brained reality shows aren't going anywhere. — 2020
3. •
   Lissencephalic; having a brain which lacks convolutions due to malformation.