octonus

Latin

Etymology

Distributive form of octō (“eight”)

Pronunciation

• (Classical Latin) IPA^(key): /okˈtoː.niː/, [ɔkˈt̪oːniː]
• (modern Italianate Ecclesiastical) IPA^(key): /okˈto.ni/, [okˈt̪ɔːni]

Adjective

octōnī (feminine octōnae, neuter octōna); first/second-declension adjective, plural only

1. eight at a time, by eights, eight each
   • c. 52 BCE, Julius Caesar, Commentarii de Bello Gallico 7.73:

     Huius generis octoni ordines ducti ternos inter se pedes distabant.

     Rows by eights of this kind were dug, they stood apart three feet between them.

   • c. 15 BCE, Vitruvius, De architectura 3.1:

     Pseudodipteros autem sic collocatur, ut in fronte et postico sint columnae octonae, in lateribus cum angularibus quindenae.

     The Pseudodipteros, however, is thus assembled so that there are eight columns each in front and rear, fifteen each on the sides including the corner ones.

   • 1611, Johannes Kepler, Strena seu de nive sexangula 20:

     Etenim si cubo adimas angulos suos octonos resectos lateribus aequalibus, introrsumque componas plane constitues octaedron.

     Moreover if you remove from a cube its eight corners each cut on equal sides, and arrange them facing inwards, you will clearly produce an octahedron.

Declension

First/second-declension adjective, plural only.

Number	Plural
Case / Gender	Masculine	Feminine	Neuter
Nominative	octōnī	octōnae	octōna
Genitive	octōnōrum	octōnārum	octōnōrum
Dative	octōnīs
Accusative	octōnōs	octōnās	octōna
Ablative	octōnīs
Vocative	octōnī	octōnae	octōna

Derived terms

• octōnārius

References

• “octonus”, in Charlton T. Lewis and Charles Short (1879) A Latin Dictionary, Oxford: Clarendon Press
• “octonus”, in Charlton T. Lewis (1891) An Elementary Latin Dictionary, New York: Harper & Brothers
• octonus in Gaffiot, Félix (1934) Dictionnaire illustré latin-français, Hachette.