Sanity.
Bits of rolled-up rubber shed by the tires of race cars that accumulate at the edges of the track, especially at the corners.
Any of several children's games played with small balls (made of marble or more commonly glass).
A mindset; a way of thinking; a set of beliefs.
The characteristics of a mind described as a system of distinctive structures and processes based in biology, language, or culture, etc.; a mental system.