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binarius

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Etymology and origin of the Latin word binarius

Confidence
Established
Formation
Derivation
First attested
354–430 AD, Augustine
Ultimate origin
Latin bīnus
Etymology tree
inherited borrowed derived
Latin binus
Latin binarius
English binary

Pronunciation

  • Classical: [biːˈnaː.ri.ʊs][1]
  • Ecclesiastical: [biˈnaː.ri.us][1]

Forms

bīnārius (feminine bīnāria, neuter bīnārium); first/second-declension adjective[1]

Etymology

It is from Latin bīnus (“twofold; two each”) + -ārius.[1][2][3] Etymonline traces bīnī further to bis (“twice”).[4]

Earliest recorded meaning

Köbler finds it first in Augustine,[3] who speaks in a sermon of a twofold division shown by the number two.[2] The Historia Augusta's life of Alexander Severus has fōrmae bīnāriae, coins worth two gold pieces, which were ordered to be melted down.[2][5]

Semantic evolution

Boethius and Favonius Eulogius use it in arithmetic.[2] In the Middle Ages it meant double, twofold,[6] and as a noun the number two: Alcuin compares the twenty in sixty with the two in six,[7] and Bartholomew the Englishman reports that some call the number two ill-famed, because it separates us from unity.[7] It was also used for a pair of contrasted things.[7]

English binary, from the mid-15th century, comes from it.[4]

Timeline

  • 354–430 AD – Augustine uses it of the number two.[2][3]
  • c. 798 – Alcuin uses the noun for the number two.[7]
  • mid-15th century – English takes binary from it.[4]

Meanings

Adjective

  1. Consisting of two; twofold, double.[5][2][6]
  2. (of coins) Worth two aurei.[5][2]
  3. (New Latin) Binary.[1]

Noun

  1. (Medieval Latin) The number two.[7]
  2. (Medieval Latin) A pair, especially of contrasted things.[7]

References

  1. ^ a b c d e Wiktionary, the free dictionary, https://en.wiktionary.org
  2. ^ a b c d e f g Thesaurus linguae Latinae (1900–), Leipzig: Teubner; Berlin: De Gruyter; open-access ed., Munich: Bayerische Akademie der Wissenschaften
  3. ^ a b c Köbler, Gerhard (2010), Lateinisches Abkunfts- und Wirkungswörterbuch für Altertum und Mittelalter, online ed., koeblergerhard.de
  4. ^ a b c Harper, Douglas. Online Etymology Dictionary, https://www.etymonline.com
  5. ^ a b c Lewis, Charlton T.; Short, Charles (1879), A Latin Dictionary, Oxford: Clarendon Press
  6. ^ a b Niermeyer, J. F. (1976), Mediae Latinitatis Lexicon Minus, Leiden: Brill
  7. ^ a b c d e f 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

Borrowed into

Cite this entry

“Binarius.” Etymologically, 23 Oct. 2026, etymologically.com/la/binarius. Accessed 23 Oct. 2026.

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