vicennalia

• Vicennalia

From Latin vīcennālia, from vīcennium (“20-year period”) + -ālia (“-alia: forming the names of festivals”), from vicennis (“20-year”) + -ium (“forming abstract nouns”), from vīciēs (“twenty each”) + annus (“year”) + -is (“forming compound adjectives”). Equivalent to vicennium +‎ -alia.

vicennalia (plural vicennalia or vicennalias)

1. (historical) The festival and religious rituals celebrating a Roman emperor's 20th year of rule.
   • 1971, P.V. Hill, "The Dating and Arrangement of Hadrian's COS III", Mints, Dies and Currency, p. 52:

     Apart from the Vicennalia, 136 was an eventful year for the imperial family: the serious illness of Hadrian in the spring, the adoption of Aelius in the summer and the death and consecration of Sabina at the end of the year.

   • 2005, Jakob Munk Højte, Roman Imperial Statue Bases from Augustus to Commodus, p. 157:

     The exact timing of the tenth and twentieth anniversaries, the decennalia and the vicennalia, has already been discussed at length. The most straightforward solution, that it took place on the emperor's dies imperii ten years after the accession, has its adherents. However, a date earlier in the year, perhaps even the day of the beginning of the tenth year, may also be considered—at least in the second century AD.

   • 2012, Gary Forsythe, "Magna Mater and the Taurobolium", Time in Roman Religion, p. 111:

     As a chronological list of Roman emperors makes clear, several rulers reign long enough to enjoy their decennalia, but relatively few were fortunate enough to celebrate their vicennalia, their twentieth imperial anniversary; and from the second century onwards Constantine alone ruled long enough to celebrate a tricennalia.

• vicennial, vicennials

• jubilee

• quinquennalia, decennalia, quindecennalia, tricennalia

• (Classical) IPA^(key): /u̯iː.kenˈnaː.li.a/, [u̯iːkɛnˈnäːlʲiä]
• (modern Italianate Ecclesiastical) IPA^(key): /vi.t͡ʃenˈna.li.a/, [vit͡ʃenˈnäːliä]

vīcennālia

1. nominative/accusative/vocative neuter plural of vīcennālis

From vīcennium (“20-year period”) +‎ -ālia (“-alia: forming the names of festivals”), from vīcennis (“20-year”) + -ium (“-ium: forming abstract nouns”), from vīciēs + annus (“year”) + -is (“forming compound adjectives”).

vīcennālia n pl (genitive vīcennālium or vīcennāliōrum); third declension

1. (historical) vicennalia, the festival and religious rituals celebrating a Roman emperor's 20th year of rule.

   vicennalia imperatorum

   20th anniversary of the emperors

Third-declension noun (neuter, “pure” i-stem), plural only.

• secundī decennālēs, decennālia altera

• quīnquennālia, decennālia, quīndecennālia, trīcennālia

• English: vicennalia, vicennial
• Italian: vicennale