tertius

From trēs (“three”), originally from Proto-Indo-European *tréyes.

• (Classical) IPA^(key): /ˈter.ti.us/, [ˈtɛr.ti.ʊs]
• (Ecclesiastical) IPA^(key): /ˈter.t͡si.us/

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

1. third, the ordinal number after secundus (“second”) and before quartus (“fourth”)

   • For quotations of use of this term, see Citations:tertius.

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

First/second declension.

• tertiārius
• tertiō

• 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)
• tertius in Gaffiot, Félix (1934) Dictionnaire Illustré Latin-Français, Hachette
• Carl Meissner; Henry William Auden (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