pi·ac·u·lar 
(pī-ăkyə-lər)
(pī-ăkyə-lər)adj.
1. Making expiation or atonement for a sacrilege: piacular sacrifice.
2. Requiring expiation; wicked or blameworthy.
[Latin piāculāris, from piāculum, propitiatory sacrifice, from piāre, to appease, from pius, dutiful.]