Parricide was the act of killing one's own parents or close relatives.
In 2375, it was revealed that the Son'a were the descendants of the peaceful Ba'ku who were subsequently ostracized by the Ba'ku for their embrace of technology. The Son'a later secretly sought revenge with their plans to conquer the Ba'ku planet within the Briar Patch whose unique radiation caused rejuvenating effects on a post-pubescent individual's physiology. Jean-Luc Picard noted that "Ru'afo's need for revenge has now escalated to parricide." (Star Trek: Insurrection)