The Buddha explains the meaning of the word world

J2 He makes clear the world is upside down.
K1 He explains the meaning of the word world.

Sutra:

Ananda, what is meant by the upside-down state of the world? All that exists comes from this; the world is set up because of the false arising of sections and shares. Every cause in fact has no cause; everything that is dependent has nothing on which it is dependent, and so it shifts and slides and is unreliable. Because of this, the world of the three periods of time and four directions comes into being. The union and interaction of times and direction bring about changes which result in the twelve categories of living beings.

Commentary:

Ananda, what is meant by the upside-down state of the world? Ananda, I will explain the inversions of the world. You should listen to this. All that exists comes from this. "This" refers to ignorance. "All that exists" refers to the physical bodies and faculties of living beings. The world is set up because of the false arising of sections and shares, of ignorance and living beings.

"Sections" refers to the individual bodies of living beings. "Shares" refers to their various lifespans. When beings give rise to ignorance, to an unenlightened thought, it is as if they have taken some drug which confuses them, or as if they had gotten drunk on too much wine. They no longer know what they should be doing. So they simply go along with their karma. Whatever karma they create, they undergo retribution for those deeds. This is why the world comes into being. Every cause in fact has no cause; everything that is dependent has nothing on which it is dependent, and so it shifts and slides and is unreliable.

Although ignorance is groundless and void, nonetheless it is the cause of this world. "No cause," then, refers to ignorance, which, being empty, cannot form a cause. And yet, illusory though it is, it gives rise to the world, "every cause." The world is empty, too, then, and since it is empty, it cannot be relied upon. And yet, it appears it can be relied upon. "Everything that is dependent has nothing on which it is dependent." Basically, the world is not something on which anything can be dependent, but because living beings give rise to false attachment and false emotion, they become something "that is dependent." This dependency is a manifestation of their karmic consciousness. But since the whole situation is basically empty, basically non-existent, basically causeless and unreliable, things "shift and slide and are unreliable."

The entire circumstance is never-ending and always in a state of flux. Because of this, the world of the three periods of time and four directions comes into being. All these influences combine to create the world. The world has three periods of time: past, present, and future. It also has four aspects of space: the four directions. The union and interaction of times and direction bring about changes which result in the twelve categories of living beings. They borrow on one another's strength. The twelve categories of living beings will be discussed below.