tricennium

plural tricennia · plural tricenniums

1. rareA period of thirty years.

   As early as the second decade after his entry into Italy Theodoric made all illegal or irregular acquisitions that had taken place prior to this fixed date [28 August 489] subject to the thirty-year statue of limitation (tricennium).

   1979, Thomas J. Dunlap, transl. Herwig Wolfram as History of the Goths, p. 298

   1 more example

   With a site I have been working with in Iceland, I am dealing with 30-year time units or tricennia, and even if it is no Pompeii, there are still features that we know represented much shorter time scales—the construction of a fireplace that could have been accomplished in a day, the placing of a coin under a timber sill beam that only took a few seconds.

   2021, Gavin Lucas, Making Time, page 48