Parricidal is a word used to describe the act of killing one's own parent or close relative. It's a strong word with a serious connotation. While there are no direct synonyms for parricidal, there are words that express similar ideas and emotions. For example, matricide is the act of killing one's mother, while patricide is the act of killing one's father. Fratricide is the act of killing one's brother, while sororicide is the act of killing one's sister. All of these words express a sense of betrayal, tragedy, and violence. While these words are not exactly synonyms for parricidal, they can be used in a similar context and can convey a similar message.