One of the biggest harms sci fi and fantays did to public scientific literacy is the abuse of the word "dimension"

D&D's astral and ethereral planes are not seperate dimenions so much as they are four-dimensional planes seperated from the really mortals live along a axis of reality.

The "11 dimensional reality" idea is an attempt to explain the asymmetry of the four fundamental forces by postulating that there are additional axis straught line axis that those forces propagate through.