The World.
from Latin mundanus, from mundus, world.
Its widely (mistaken use...) used as the meaning of normal, earthly, to distinct regular person from a gifted/special one...
why is it a mistake... since time has changed the meaning of this word ... misunderstanding the meaning of WORLD or EARTH as Regular or Not Special .... making us a Regular and everything else is : Special in a good way... or a better than the mundane one...
Mundane means the world... and the world is everything but Regular the world/earth(and all the rest...) is incredible... we havent even started to understand it ... let alone tag it as something less than anything... etc.