quindecennalia

Etymology
From, from + , from  +. Equivalent to or.

Noun

 * 1)  The festival and religious rituals sometimes observed celebrating a Roman emperor's 15th year of rule.
 * 2) * 1837, Edward Burton, Lectures upon the Ecclesiastical History of the First Three Centuries..., Vol. II, "Lecture XIV", p. 40:
 * There is evidence, that the quindecennalia, of fifteenth anniversary of Trajan's proconsular authority, and of his adoption to the empire, was celebrated in 111, or the year after Pliny's arrival in Bithynia.

Translations

 * Latin: quīndecennālia