From Proto-Indo-European *nu (“now; well; and”) + diūs, reflecting the original nom.sg. of diēs (“day”) that was later remodelled on the accusative. The former component cognate to Latin num (“interrogative particle”), nunc (“now”), nūper (“lately, recently”); its length is uncertain, since the original short vowel of PIE appears to have undergone lengthening in numerous daughter languages, with both Sanskrit and Greek showing both variants. The original nominative also surfaces in me-diū̆s-Fidius (“so help me God”, interjection) as well as in diurnus; whether it retained the length of the ū cannot be established. The uncertainty over etymological vowel lengths is compounded by the fact that both the scansions nŭdĭū̆s (with anceps third syllable) and nūdĭŭ(s) (with s-loss or iambic shortening) are possible in all the occurrences except one, where nū- is required.
- (Classical) IPA(key): /ˈnu.di.uːs/, [ˈnʊd̪iuːs̠] or IPA(key): /ˈnu.di.us/, [ˈnʊd̪iʊs̠]
- (Classical) IPA(key): /ˈnuː.di.uːs/, [ˈnuːd̪iuːs̠] or IPA(key): /ˈnuː.di.us/, [ˈnuːd̪iʊs̠]
- (Ecclesiastical) IPA(key): /ˈnu.di.us/, [ˈnuːd̪ius]
- Note: which /u/ was long and short is impossible to establish - see Etymology.
nū̆diū̆s (not comparable)
- (with an ordinal number) (...−1) days ago; literally "it is now the ...th day since"
- Nudius tertius.
- Day before yesterday. (It is now the third day)
- Nudius quartus.
- Day before the day before yesterday; three days ago. (Not four. Latin day counting included both endpoints; if three days ago is the first day, it is now the fourth day.)
- Nudius tertius decimus.
- Twelve days ago.
- Nam ego Lemno advenio Athenas nudius tertius.
- Now I reach Athens from Lemnos the day before yesterday.
- Nudius sextus cui talentum mutuum dedi, reposcam.
- It is now the sixth day since I demanded back the borrowed talent whom I have given.
- Heia, nudius quintus natus quidem ille est.
- Why, indeed it is now the fifth day since he was born.
- Recordamini qui dies nudius tertius decimus fuerit.
- Recollect what a day it was twelve days ago.
- Heri et nudius tertius, quartus, quintus, sextus...
- Yesterday and the day before yesterday, and the day before that, and the day before that, and the day before that.
- Nudius tertius dedi ad te epistulam longiorem.
- I gave you the longer letter the day before yesterday.
- Nudius tertius.
- Neapolitan: nustierzu (“the day before yesterday”), nustersu, nustiersu, nnustierzu, nnustersu, lustierzu (Calabria)
- English: nudiustertian
- De Vaan, Michiel (2008), “diū, diu”, in Etymological Dictionary of Latin and the other Italic Languages (Leiden Indo-European Etymological Dictionary Series; 7), Leiden, Boston: Brill, →ISBN, page 172
- nudius in Charlton T. Lewis and Charles Short (1879) A Latin Dictionary, Oxford: Clarendon Press
- nudius in Charlton T. Lewis (1891) An Elementary Latin Dictionary, New York: Harper & Brothers
- nudius in Charles du Fresne du Cange’s Glossarium Mediæ et Infimæ Latinitatis (augmented edition with additions by D. P. Carpenterius, Adelungius and others, edited by Léopold Favre, 1883–1887)
- nudius in Gaffiot, Félix (1934) Dictionnaire illustré Latin-Français, Hachette
- nudius in Ramminger, Johann (accessed 16 July 2016) Neulateinische Wortliste: Ein Wörterbuch des Lateinischen von Petrarca bis 1700, pre-publication website, 2005-2016