The Collaborative International Dictionary of English v.0.48:

Parricide \Par"ri*cide\, n. [F., fr. L. parricida; pater father
   + caedere to kill. See Father, Homicide, and cf.
   Patricide.]
   [1913 Webster]
   1. Properly, one who murders one's own father; in a wider
      sense, one who murders one's father or mother or any
      ancestor.
      [1913 Webster]

   2. [L. parricidium.] The act or crime of murdering one's own
      father or any ancestor.
      [1913 Webster]

WordNet (r) 3.0 (2006):

parricide
    n 1: someone who kills his or her parent
    2: the murder of your own father or mother