Prone to killing off the fruits of good karma by performing bad actions, hence, mean or evil to others. Compare with kargasm, karspasm, and karplastic.
He was deemed karmacidal because of his evil actions to take advantage of others for his own benefit.
conservative christian: if you kill yourself you're going to burn for eternity in the depths of hell.
random dude: sod off man, i'm karmacidal.