Why “piaculum” is a great word
PIACULUM — [Noun] An expiatory sacrifice, the victim of such a sacrifice, or an act requiring expiation. From the Latin piāculum ("means of atonement, expiatory sacrifice"), from piāre ("to appease, atone for"). Unlike hostia, a general sacrificial offering to a deity, or lustratio, a purificatory rite, a piaculum is the specific, heavy price demanded for a breach of the sacred order. It is the black goat driven over a cliff, the unblemished lamb whose throat is cut at the altar, and the scapegoat burdened with a tribe's guilt—the irrevocable calculus by which a community convinces itself it is clean again.