piacular
Requiring atonement or reparation: wicked, sinful, bad.
And while we think it ſo piaculous, to go beyond the Ancients; we muſt neceſſarily come ſhort of genuine Antiquity, Truth; unleſs we ſuppoſe them to have reach'd perfection of Knowlege in ſpight of their own acknowledgments of Ignorance.
Expiatory; serving to atone.
The piacular sacrifice arose from the need of atoning for bloodshed within the kinship group ; properly speaking, the culprit himself should suffer : should he be unknown or beyond the reach of vengeance, a substitute had to be found[…]
Where it comes from
Early 17th century, from French piaculaire, from Latin piacularis, derived from piaculum, from piō (“to appease, purify, expiate”) +-culum (instrumental suffix).
Adapted from the Wiktionary entry piacular (CC BY-SA 4.0).