Lewis & Short

parrĭcīdĭum, ii, n. [parricida], the murder of one’s father or parents, parricide.

  1. I. Lit.: patris et patrui parricidium, Cic. Phil. 3, 7, 18; id. Rosc. Am. 26, 73.
    1. B. Trop., parricide: vituperare quisquam vitae parentem (philosophiam) et hoc parricidio se inquinare audet? Cic. Tusc. 5, 2, 6.
  2. II. Transf.
    1. A. The murder of one’s mother, brother, relation, etc.: matris, Suet. Ner. 34: fraternum, Cic. Clu. 11, 31: fratris, Liv. 40, 24: filii, id. 8, 11: patrui, Cic. Phil. 3, 7, 18: lege Pompeia de parricidiis tenetur, qui patrem, matrem, avum, aviam, fratrem, sororem, patruelem, matruelem … patronum, patronam . . . occiderit, etc., Paul. Sent. 5, 24, 1.
      Absol., Cic. N. D. 3, 26, 67; Quint. 9, 288; Just. 1, 9: ne parricidio macularent partus suos, nepotum illi, liberūm hi progeniem, Liv. 1, 13, 2; Just. 17, 1.
    2. B. In gen., of any horrible crime; of the murder of a free citizen: facinus est vinciri civem Romani: scelus verberari: prope parricidium necari, Cic. Verr. 2, 5, 66, § 170.
      Of treason, rebellion (cf. parricida, II. D.): patriae, Cic. Phil. 2, 7, 17; id. Sull. 2, 7; id. Off. 3, 21, 83: publicum, Liv. 28, 29: parricidii quaestores appellabantur, qui solebant creari causā rerum capitalium quaerendarum. Nam parricida non utique is, qui parentem occidisset, dicebatur, sed qualemcumque hominem indemnatum, Fest. p. 221 Müll.
      Hence,
      1. 2. Transf., a name of the Ides of March, as the day when Cæsar was killed: Idus Martias parricidium nominari (placuit), Suet. Caes. 88.