peripeteia

1. (drama) A sudden reversal of fortune as a plot point in Classical tragedy.countableuncountable

2. (by extension) Any sudden change in circumstances; a crisis.Examples: "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."; "They were to bestride the Algerian scene like demigods until the tragic peripeteia of 1961 […]"broadlycountableuncountable

3. (psychoanalysis) A turning point in psychosocial development.Examples: "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.""countableuncountable