Of what origin is the word "chaos"?

The word "chaos" is borrowed from Ancient Greek χάος (kháos, “vast chasm, void”).

In Early Modern English it is used in the sense of the original Greek word. In the meaning of "primordial matter" it starts being used from the 16th century. The figurative usage of the word "chaos" in the sense of "confusion, disorder" appears from the 17th century. The technical sense in mathematics and science dates to the 1960s.

Some of the meanings of the word "chaos" can be found below:

1. A vast chasm or abyss.

2. The unordered state of matter in classical accounts of cosmogony.

3. Any state of disorder, any confused or amorphous mixture or conglomeration.

4. A given medium; a space in which something exists or lives; an environment.

5. Behavior of iterative non-linear systems in which arbitrarily small variations in initial conditions become magnified over time.

6. One of the two metaphysical forces of the world in some fantasy settings, as opposed to law.