Etymologically

Etymology and origin of the Latin word inopinus

Confidence
Probable
Formation
Back-formation
First attested
70–19 BC, Virgil
Ultimate origin
Latin (opīnor)
Etymology tree
inherited borrowed derived
Latin inopinatus
Latin inopinus

Pronunciation

  • Classical: [ɪ.nɔˈpiː.nʊs][1]
  • Ecclesiastical: [i.noˈpiː.nus][1]

Forms

inopīnus (feminine inopīna, neuter inopīnum); first/second-declension adjective[1]

Etymology

It is from Latin inopīnātus (“unexpected”), a back-formation according to the OLD and the TLL, like necopīnus.[2][3] Georges and Wiktionary instead analyse it as ⟨in-⟩ with an adjective ⟨*opīnus⟩ from opīnor (“to suppose”).[4][1] De Vaan finds no convincing etymology for that verb.[5]

Earliest recorded meaning

It is found from Virgil on:[3][6] in the Aeneid an unexpected rest has relaxed someone's limbs, inopīna quiēs.[2][7]

Semantic evolution

Virgil also has an unforeseen face of trouble and an unexpected chance, and Ovid an unforeseen sight and an unexpected war.[2][8] In prose it is found from Tacitus on, and Ammianus Marcellinus uses it often.[3] Statius and Silius Italicus use it of a person or animal caught off guard.[2][7] The grammarian Servius remarked that in Virgil it is an adjective and not a participle.[3]

Medieval writers kept both senses, “unexpected” and “taken by surprise”, and used inopīnē as an adverb, “suddenly”.[9][10]

Timeline

  • 70–19 BC – Virgil uses it of an unexpected sleep.[2][6]
  • 43 BC–18 AD – Ovid uses it of an unforeseen sight.[8][6]
  • c. 45–96 AD – Statius uses it of a man caught off guard.[2][6]
  • 98–115 AD – Tacitus uses it in prose.[3][6]
  • c. 390 AD – Ammianus Marcellinus uses it often.[3][6]

Meanings

Adjective

  1. Unexpected, unforeseen.[2][8]
  2. Off one's guard, unsuspecting.[2][7]

References

  1. ^ a b c d Wiktionary, the free dictionary, https://en.wiktionary.org
  2. ^ a b c d e f g h Glare, P. G. W., ed. (2012), Oxford Latin Dictionary, 2nd ed., Oxford: Oxford University Press
  3. ^ a b c d e f Thesaurus linguae Latinae (1900–), Leipzig: Teubner; Berlin: De Gruyter; open-access ed., Munich: Bayerische Akademie der Wissenschaften
  4. ^ Georges, Karl Ernst (1913–1918), Ausführliches lateinisch-deutsches Handwörterbuch, 8th ed., ed. Heinrich Georges, Hannover; Leipzig: Hahn
  5. ^ de Vaan, Michiel (2008), Etymological Dictionary of Latin and the other Italic Languages, Leiden Indo-European Etymological Dictionary Series 7, Leiden; Boston: Brill
  6. ^ a b c d e f Köbler, Gerhard (2010), Lateinisches Abkunfts- und Wirkungswörterbuch für Altertum und Mittelalter, online ed., koeblergerhard.de
  7. ^ a b c Conte, Gian Biagio; Pianezzola, Emilio; Ranucci, Giuliano (2010), il Latino: Vocabolario della lingua latina, 3rd ed., Florence: Le Monnier
  8. ^ a b c Lewis, Charlton T.; Short, Charles (1879), A Latin Dictionary, Oxford: Clarendon Press
  9. ^ Mittellateinisches Wörterbuch bis zum ausgehenden 13. Jahrhundert (1967–), Munich: C. H. Beck; Bayerische Akademie der Wissenschaften
  10. ^ Latham, R. E., D. R. Howlett, R. K. Ashdowne, et al. (1975–2013), Dictionary of Medieval Latin from British Sources, London: British Academy / Oxford University Press
Cite this entry

“Inopinus.” Etymologically, 20 Oct. 2026, etymologically.com/la/inopinus. Accessed 20 Oct. 2026.

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