octodecim

Latin

Latin numbers ^(edit)

[a], [b], [c], [d] ←  17	XVIII 18	19  → [a], [b], [c]
Cardinal: duodēvīgintī, decem et octō, octōdecim, ogdecim     Ordinal: duodēvīcēsimus, decimus octāvus, octāvus decimus, octōdecimus     Adverbial: octōdeciēs     Proportional: octōdecuplus     Distributive: duodēvīcēnus, octōnus dēnus

Alternative forms

• Symbol: XVIII

Etymology

From octō (“eight”) + decem (“ten”).

Pronunciation

• (Classical Latin) IPA^(key): [ɔkˈtoː.dɛ.kĩː]
• (modern Italianate Ecclesiastical) IPA^(key): [okˈt̪ɔː.d̪e.t͡ʃim]

Numeral

octōdecim (indeclinable)

1. (rare) eighteen; 18
   • 1543, Petrus Comestor, Historia Scholastica, III Kings, "De porticu"

     Quarum talis erat compositio: Stylus, vel stipes columnae octodecim habebat cubitos altitudinis

     (please add an English translation of this quotation)

   • 1687, Isaac Newton, “Axiomata, sive Leges Motus”, in Philosophiae Naturalis Principia Mathematica:

     Si corpus Alucretur partes novem vel decem vel undecim vel duodecim, adeoque progrediatur post concursum cum partibus quindecim vel sexdecim vel septendecim vel octodecim.

     (please add an English translation of this quotation)

Usage notes

This form is rare, and is found primarily in bookish post-Classical Latin. The usual word for eighteen in Classical Latin is duodēvīgintī, whereas modern Romance languages descend from the form decim et octō.

Synonyms

• duodēvīgintī

See also

• Appendix:Latin cardinal numbers

References

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