What does 'corrupted' (world or society) mean?

The translation of "corruption" & "corrupt" is found in many places in the Pali suttas, such as:

As to this, bhikkhus, there is a threefold corruption and failure of bodily kamma, arisen from unwholesome volition, having a painful outcome and result; a fourfold corruption and failure of verbal kamma, arisen from unwholesome volition, having a painful outcome and result; and a threefold corruption and failure of mental kamma, arisen from unwholesome volition, having a painful outcome and result.

It is, bhikkhus, because of the threefold corruption and failure of bodily kamma, arisen from unwholesome volition … or it is because of the fourfold corruption and failure of verbal kamma, arisen from unwholesome volition … or it is because of the threefold corruption and failure of mental kamma, arisen from unwholesome volition, that with the breakup of the body, after death, beings are reborn in the plane of misery, in a bad destination, in the lower world, in hell.

AN 10.218

While the world can never be perfect, a morally uncorrupted world is described in many places in the Pali suttas, including simply as the Six-Directions & the respective duties/relationship obligations expounded within. A departure from the kammic lawfulness of the Six Directions is a corruption (rather than something "progressive").

And how, young householder, does a noble disciple cover the six quarters?

The following should be looked upon as the six quarters. The parents should be looked upon as the East, teachers as the South, wife and children as the West, friends and associates as the North, servants and employees as the Nadir, ascetics and brahmans as the Zenith

DN 31 Sigalovada Sutta The Layperson's Code of Discipline

Or the Conditions of a Nation's Welfare:

So long, brahman, as these endure among the Vajjis, and the Vajjis are known for it, their growth is to be expected, not their decline.

DN 16

The cause & condition for the creation & maintenance of the human world is wholesome sexual & family conduct. While the world has periodically engaged in wars & other unwholesome actions, a departure from wholesome sexual & family conduct is the primary cause of the corruption of the human world & regression into an animal, hell &/or hungry ghost world.

Bhikkhus, these two bright principles protect the world. What are the two? Shame and fear of wrongdoing. If, bhikkhus, these two bright principles did not protect the world, there would not be discerned respect for mother or maternal aunt or maternal uncle's wife or a teacher's wife or the wives of other honored persons, and the world would have fallen into promiscuity, as with goats, sheep, chickens, pigs, dogs, and jackals. But as these two bright principles protect the world, there is discerned respect for mother... and the wives of other honored persons.

AN 2.9

I'd say it's idiosyncratic. Each school has a somewhat different take on it. In Zen, we often refer to corruption as "red dust". Han Shan, for instance, refers to it often:

I was born just thirty years ago,
but I’ve wandered a million miles already.
Along the River through the green grass on the
banks, out to the borderlands, where the red dust roils.

I think the footnote in my copy of his poetry does an excellent job of explaining this idea:

"The word we usually translate as “dust,” or “the red dust,” is a conventional epithet for the klesas, or “defilements,” of life in the everyday world, everything from simple dirt, to the deep moral defilements we accept in the compromises and little hypocrisies of everyday lay living."

From Cold Mountain Poems translated by J.P Seaton