shirt of Nessus
an inescapable ruin
Today this word meansA doom there is no escaping — the kind that begins the moment you take hold of it.
The dying centaur left his blood behind; believing it a love charm, she smeared it on a robe — and Heracles burned to death in it.
The heart of the metaphor: once on, it cannot come off, and it tears the flesh away with it.