peripeteia
A sudden reversal of fortune as a plot point in Classical tragedy.
countable, uncountable
If we recoil with the consternation of surprise at such a conclusion, it is no defense to invoke as parallel the peripeteia by which Euripides in his Ion leads us to expect one ending yet effects another.
Any sudden change in circumstances; a crisis.
countable, uncountable
Once more I was a man in a myth, incapable of understanding it, but somehow aware that understanding it meant it must continue, however sinister its peripeteia.
A turning point in psychosocial development.
countable, uncountable
The visual moment whose consequences Freud began to ponder in the essay on the phallic stage has evolved into a peripeteia: "Some day or other it happens that the child whose own penis is such a proud possession obtains a sight of the genital parts of a little girl; he must then become convinced of the absence of a penis in a creature so like himeself. With this, however, the loss of his own penis becomes imaginable, and the threat of castration achieves its delayed effect."
Where it comes from
From Late Latin peripetia, and its source Ancient Greek περιπέτεια (peripéteia), from περιπίπτω (peripíptō, “to change suddenly”), from περί (perí, “round, around, about”) + the stem of πίπτω (píptō, “to fall”).
Adapted from the Wiktionary entry peripeteia (CC BY-SA 4.0).