Definition 2023




Latin ordinal numbers
 <  2nd 3rd 4th  > 
    Cardinal : tres
    Ordinal : tertius
    Adverbial : ter
    Multiplier : triplex
    Distributive : ternī


tertius m (feminine tertia, neuter tertium); first/second declension

  1. (ordinal) third, the ordinal number after secundus (second) and before quartus (fourth)
    • For usage examples of this term, see Citations:tertius.

Usage notes

  • In poetical sense it is used for the Roman "Third World", that is the "Underworld", of Pluto


First/second declension.

Number Singular Plural
Case / Gender Masculine Feminine Neuter Masculine Feminine Neuter
nominative tertius tertia tertium tertiī tertiae tertia
genitive tertiī tertiae tertiī tertiōrum tertiārum tertiōrum
dative tertiō tertiō tertiīs
accusative tertium tertiam tertium tertiōs tertiās tertia
ablative tertiō tertiā tertiō tertiīs
vocative tertie tertia tertium tertiī tertiae tertia

Derived terms



  • tertius in Charlton T. Lewis and Charles Short (1879) A Latin Dictionary, Oxford: Clarendon Press
  • tertius in Charlton T. Lewis (1891) An Elementary Latin Dictionary, New York: Harper & Brothers
  • TERTIUS in Charles du Fresne du Cange’s Glossarium Mediæ et Infimæ Latinitatis (augmented edition, 1883–1887)
  • Félix Gaffiot (1934), “tertius”, in Dictionnaire Illustré Latin-Français, Paris: Hachette.
  • Meissner, Carl; Auden, Henry William (1894) Latin Phrase-Book, London: Macmillan and Co.
    • it is the third hour (= 9 A.M.: tertia hora est
    • I am in my thirteenth year: tertium decimum annum ago
    • to be middle-aged (i.e. between thirty and forty): tertiam iam aetatem videre
    • to admit another into the circle of one's intimates: aliquem (tertium) ad (in) amicitiam ascribere
    • the actor who plays the leading part: actor primarum (secundarum, tertiarum) partium
    • consul for the second, third time: iterum, tertium consul