1. "person who kills his father" (1590s), 2. "act of killing one's father" (1620s), from Middle French patricide in both senses, from 1. Latin patricida "murderer of a father," 2. Latin patricidium, from pater "father" + 1. cida "killer," 2. cidium "killing" (see -cide).[patricide etymology, patricide origin, 英语词源]