VICENNIAL
Source: 567
Vi‐cen″ni‐al (?), a. [[L. vicennium a period of twenty years; viceni twenty + annus year.]] 1. 1. Lasting or comprising twenty years.
2. 2. Happening once in twenty years; as, a vicennial celebration.
Source: 567
Vi‐cen″ni‐al (?), a. [[L. vicennium a period of twenty years; viceni twenty + annus year.]] 1. 1. Lasting or comprising twenty years.
2. 2. Happening once in twenty years; as, a vicennial celebration.