dubius

Somewhat uncertain, but likely derived from *dubos (“in doubt”, adj.), from Proto-Italic *du(i)βwos, from Proto-Indo-European *dwi- (“two-”) + *bʰuH- (“to be”), with the same latter element as in superbus, probus (less likely tribus), in this case parallel to Ancient Greek διφυής (diphuḗs, “of two shapes or natures”). Or less likely, directly from Proto-Indo-European *dubʰi- (“on two sides”).

For the relation to "two" cf. Ancient Greek δισσός (dissós, “twofold; doubtful”), δοιάζω (doiázō, “to be in two minds”) and German Zweifel (“doubt”).

• (Classical) IPA^(key): /ˈdu.bi.us/, [ˈd̪ʊbiʊs̠]
• (modern Italianate Ecclesiastical) IPA^(key): /ˈdu.bi.us/, [ˈd̪uːbius]

dubius (feminine dubia, neuter dubium); first/second-declension adjective

1. Moving in two directions alternately, vibrating to and fro, fluctuating, wavering
2. (figuratively) Vacillating in mind, uncertain; doubting, doubtful, dubious, irresolute, undetermined

   Synonyms: incertus, suspensus, vagus, anceps

   Antonyms: fixus, prōmptus, indubius

3. (of a situation) Precarious, dangerous, critical, difficult, adverse, doubtful, in doubt

   Synonyms: perīculōsus, īnfēnsus, anceps, capitālis

   • 8 CE, Ovid, Fasti 2.781:

     exitus in dubiō est

     The result is in doubt

4. (of weather) Changeable, uncertain

First/second-declension adjective.

• → English: dubious
• → Italian: dubbio
• → Portuguese: dúbio
• → Sicilian: dùbbitu

• De Vaan, Michiel (2008) “dubius”, in Etymological Dictionary of Latin and the other Italic Languages (Leiden Indo-European Etymological Dictionary Series; 7), Leiden, Boston: Brill, →ISBN, page 180
• Walde, Alois, Hofmann, Johann Baptist (1938) “dubius”, in Lateinisches etymologisches Wörterbuch (in German), 3rd edition, volume 1, Heidelberg: Carl Winter, page 375

• “dubius”, in Charlton T. Lewis and Charles Short (1879) A Latin Dictionary, Oxford: Clarendon Press
• “dubius”, in Charlton T. Lewis (1891) An Elementary Latin Dictionary, New York: Harper & Brothers
• dubius 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)
• dubius in Gaffiot, Félix (1934) Dictionnaire illustré latin-français, Hachette.
• Carl Meißner, Henry William Auden (1894) Latin Phrase-Book‎, London: Macmillan and Co.
  • a critical position; a hopeless state of affairs: res dubiae, perditae, afflictae
    
  • vague rumours reach us: dubii rumores afferuntur ad nos
    
  • to throw doubt upon a thing: in dubio ponere
    
  • to leave a thing undecided: aliquid in medio, in dubio relinquere (Cael. 20. 48)
    
  • without doubt, beyond all doubt: sine dubio (not sine ullo dubio)
    
  • (ambiguous) to throw doubt upon a thing: in dubium vocare
    
  • (ambiguous) to become doubtful: in dubium venire
    
  • (ambiguous) to leave a thing undecided: aliquid dubium, incertum relinquere