octodecim

Latin

**Latin numbers ^(edit)**
^{[a], [b], [c], [d]} ← 17	XVIII 18	19 → ^{[a], [b], [c]}
Cardinal: duodēvīgintī, octōdecim, ogdecim Ordinal: duodēvīcēsimus, decimus octāvus, octāvus decimus, octōdecimus Adverbial: octodecies Proportional: octodecuplus Distributive: duodēvīcēnus

Alternative forms

Symbol: XVIII

Etymology

From octō (“eight”) + decem (“ten”).

Pronunciation

(Classical Latin) IPA^(key): /okˈtoː.de.kim/, [ɔkˈt̪oːd̪ɛkɪ̃ˑ]
(modern Italianate Ecclesiastical) IPA^(key): /okˈto.de.t͡ʃim/, [okˈt̪ɔːd̪et͡ʃim]

Numeral

octōdecim (indeclinable)

(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

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.