World: Ambiguous term for the planet earth,
nature or a set of assumptions and
practices that make one a member of some
The last sense was introduced by the
existentialists, with considerable justification, apart from the
tenability of existentialism, because it is true that the human life
most persons lead happens mostly in terms
of assumptions and practices that make one
a member of some human society.
Indeed, being a person involves - apart
from madness, illness, sleep and unconsciousness - playing
Also, logic has contributed the notion of possible world: Whatever entities in one of various domains that satisfy some set of assumptions. This was introduced to consider various alternatives to what is so in fact: In another possible world you might have been taller, smarter, richer or perhaps not exist at all.