"Chaos" is another Greek word, and it has the same Indo-European root as our word "yawn," meaning a gap, a chasm. More than a century before Anaximander, the poet Hesiod used it to name the emptiness that was at the very beginning, before, as he put it, "broad-bosomed Earth appeared, sure standing place for all the gods." Today "chaos" has acquired a new meaning, a mathematical concept having nothing at all to do with the ápeiron, except perhaps for the boundless snobbery of those who use it, thoughtlessly, where it doesn't belong. To get a pretty good idea of how the word chaos is used in math, read Ekeland's book, Mathematics and the Unexpected.