Etymology 1Edit

From Proto-Italic *enratos, from *en- + *ratos, whence also Latin ratus, past participle of *rēōr, whence Latin reor, ultimately from Proto-Indo-European *h₁er-.

Alternative formsEdit



irritus (feminine irrita, neuter irritum); first/second-declension adjective

  1. invalid, void, null and void
    • 121 CE, Suetonius, De vita Caesarum VI.33:
      Certē omnibus rērum verbōrumque contumēliīs mortuum īnsectātus est, modo stultitiae modo saevitiae arguēns; nam et mōrārī eum dēsīsse inter hominēs prōductā prīmā syllabā iocābātur multaque dēcrēta et cōnstitūta, ut īnsipientis atque dēlīrī, prō irritīs habuit.
      He certainly blamed the dead one [Claudius] with all insults, of deeds and of words, sometimes reproving his stupidity, other times his cruelty; for he jested about him having ceased to be a fool among people (with a lengthened first syllable) as well as having many decrees and edicts of his void, as if those of an unwise and crazy one.
  2. ineffective, useless, irrelevant

First/second-declension adjective.

Number Singular Plural
Case / Gender Masculine Feminine Neuter Masculine Feminine Neuter
Nominative irritus irrita irritum irritī irritae irrita
Genitive irritī irritae irritī irritōrum irritārum irritōrum
Dative irritō irritō irritīs
Accusative irritum irritam irritum irritōs irritās irrita
Ablative irritō irritā irritō irritīs
Vocative irrite irrita irritum irritī irritae irrita

Etymology 2Edit

See the etymology of the main entry.



irrītus m (genitive irrītūs); fourth declension

  1. Alternative form of hirrītus

Fourth-declension noun.

Case Singular Plural
Nominative irrītus irrītūs
Genitive irrītūs irrītuum
Dative irrītuī irrītibus
Accusative irrītum irrītūs
Ablative irrītū irrītibus
Vocative irrītus irrītūs


  • irritus in Charlton T. Lewis and Charles Short (1879) A Latin Dictionary, Oxford: Clarendon Press
  • irritus in Gaffiot, Félix (1934) Dictionnaire illustré Latin-Français, Hachette
  • Carl Meissner; Henry William Auden (1894) Latin Phrase-Book[1], London: Macmillan and Co.
    • to frustrate, nullify: ad irritum redigere aliquid
    • expectation is overthrown: spes ad irritum cadit, ad irritum redigitur
    • to annul, revoke a will: testamentum irritum facere, rumpere
    • a law is valid: lex rata est (opp. irrita)
  • Pokorny, Julius (1959) Indogermanisches etymologisches Wörterbuch [Indo-European Etymological Dictionary] (in German), volume I, Bern, München: Francke Verlag, page 326