LATIN DICTIONARYLexicon Latīnum
adjectivefirst/second-declension adjective

irritus

irritus (feminine irrita, neuter irritum, comparative irritior, superlative irritissimus, adverb irritē)
Classical[ˈɪr.rɪ.tʊs]Ecclesiastical[ˈir.ri.tus]

Meaning

  1. adjectiveinvalid, void, null and void
    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.121 CE, Suetonius, De vita Caesarum VI 33
  2. adjectiveineffective, useless, irrelevant
    inrita fallaci quotiens dedit oscula fonti!How often he [Narcissus] gave futile kisses to the deceptive fountain!8 CE, Ovidius, Metamorphoses III.427

Latīnē defined in Latin in our graded readers

Choosing the right word Döderlein's Latin Synonyms

Frustra · Nequidquam · Incassum · Irritus

1. Frustra (from ψύθος) means in vain, with reference to the subject, whose expectation and calculations have been disappointed; whereas nequidquam (that is, in nequidquam, in nihil), to no purpose, refers to the nullity in which the thing has ended. 2. Hence frustra, used adjectively, refers to the person; whereas irritus, the actual adjective, refers to the thing. 3. Frustra and nequidquam denote merely a failure, without imputing a fault, like μάτην; whereas incassum involves the accessory notion of a want of consideration, by which the failure might have been calculated upon, and foreseen, as in attempting any thing manifestly or proverbially impossible, εἴς κενόν. (iii. 100.)

Declension

singular
formmasculinefeminineneuter
nominativeirritusirrita
inrita		irritum
inritum
genitiveirritī
inritī		irritae
inritae		irritī
inritī
dativeirritō
inritō		irritae
inritae		irritō
inritō
accusativeirritum
inritum		irritam
inritam		irritum
inritum
ablativeirritō
inritō		irritā
inritā		irritō
inritō
vocativeirrite
inrite		irrita
inrita		irritum
inritum
plural
formmasculinefeminineneuter
nominativeirritī
inritī		irritae
inritae		irrita
inrita
genitiveirritōrum
inritōrum		irritārum
inritārum		irritōrum
inritōrum
dativeirritīs
inritīs		irritīs
inritīs		irritīs
inritīs
accusativeirritōs
inritōs		irritās
inritās		irrita
inrita
ablativeirritīs
inritīs		irritīs
inritīs		irritīs
inritīs
vocativeirritī
inritī		irritae
inritae		irrita
inrita

Phrases from Meissner's Latin Phrase-Book

ad irritum redigere aliquid
to frustrate, nullify.
testamentum irritum facere, rumpere
to annul, revoke a will.
spes ad irritum cadit, ad irritum redigitur
expectation is overthrown.

irrĭtus (inr-), a, um, adj. 2. inratus,
I. invalid.
I. Lit.
A. Undecided, unfixed, void, of no effect: quod modo erat ratum, irritum est, Ter. Phorm, 4, 7, 58: testamentum irritum facere, Cic. Phil. 2, 42, 109: testamentum pro irrito habere, Suet. Tib. 51; Gai. Inst. 2, 146 sq.; Paul. Sent. 3, 5, 14: injurias rescindere et irritas facere, Cic. Verr. 2, 2, 26, § 63: quaeque augur injusta, nefasta, vitiosa, dira, defixerit, inrita infectaque sunto, id. Leg. 2, 8, 21: omnia ab iis acta, Vell. 2, 43, 1: pacta, Sil. 6, 696: Tiberii voluntas, Suet. Calig. 14: somnia, of no significance, id. Aug. 91: Remus aves irritas habuit, Gell. 13, 14.—
B. Vain, useless, without effect, ineffectual: ingrata atque irrita esse omnia intellego, Plaut. As. 1, 2, 10: inceptum, Liv. 29, 35; 24, 19: dona, Verg. G. 4, 519: tela, id. A. 2, 459: moenia, Ov. M. 12, 587: labor anni, id. ib. 1, 273; Quint. 12, 1, 13: verba, Ov. R. Am. 286: tua dicta factaque, Cat. 30, 10: spes, Liv. 22, 20; Stat. Th. 10, 45: oblivio, Liv. 28, 29: lingua (Cassandrae), Prop. 3, 13 (4, 12), 66: remedium, Tac. H. 4, 81: preces, Plin. Pan. 26: ova, fruitless, infertile, Plin. 10, 58, 79, § 160.—
II. Transf., of persons, that does or undertakes a thing in vain, to no purpose, without effect.
(a). With gen.: irritus legationis, Tac. H. 4, 32: consilii, Vell. 2, 63, 2: propositi, Val. Max. 4, 3, 3 ext.: spei, vainly hoping, Curt. 6, 5, 31: incepti, Sil. 7, 131.—
(b). Absol.: variis assultibus irritus urget, Verg. A. 5, 442: venit et e templis irrita turba domum, without a response, Tib. 2, 3, 22: irriti legati remittuntur, Tac. A. 15, 25: domum irritus rediit, Sen. Ben. 6, 11: discedere irritum putebat, Curt. 4, 4, 2: irritus qui habebatur, laudabatur, good for nothing, Cat. ap. Gell. 11, 2, 2.—Subst.: irrĭtum, i, n., nothingness, vanity, worthlessness: spes ad irritum redacta, Liv. 28, 31: spes ad irritum cadens, id. 2, 6: victoria ad inritum revolvebatur, Tac. H. 3, 26: cecidisse in inritum labores, id. ib. 3, 53 fin.: irrita dicere, useless words, Ov. M. 11, 40.—Adv.: irrĭtē, in vain, Cassiod. Var. 1, 4; 12, 2.
irrītus, ūs, m., v. hirritus.

Origins

  1. Proto-Indo-European*né
  2. Proto-Indo-European*n̥-
  3. Proto-Italic*n̥-
  4. Latinirritus

Latin ratus Latin irritus From in- + ratus (“established”).

Descendants
  • Italianirrito
  • Spanishírrito

Quick answers

What does irritus mean in Latin?
irritus, a adjective, means “invalid, void, null and void; ineffective, useless, irrelevant”.
How do you pronounce irritus?
In classical Latin, [ˈɪr.rɪ.tʊs]; in ecclesiastical (church) Latin, [ˈir.ri.tus].
Where does irritus come from?
Proto-Indo-European *né → Proto-Indo-European *n̥- → Proto-Italic *n̥- → Latin irritus.