duodecade

Borrowed from Late Latin duodecas (“twelve”), from Ancient Greek δυωδεκάς (duōdekás, “twelve”). Equivalent to duodeca- +‎ -ade.

duodecade (plural duodecades)

1. A period of twelve years.

   Each Chinese New Year during a "Jupiter return"—when a duodecade has passed and the Chinese zodiac animal of your birth year comes back around—it is expected that you find some red underwear to put on for the special occasion.

   • 1880, The Popular Science Monthly, page 471:

     A second part is meadow-land, and every twelve years this is divided into as many parts as there are holders of village rights, and each one receives a share, of which he has the exclusive use until the redivision at the end of the duodecade.

• dodecade (less common)

• (group) monad, duad/dyad, triad, tetrad, pentad, hexad, hebdomad/heptad, ogdoad/octad, ennead/nonad, decad/decade, hendecad, dodecad/duodecade, chiliad

• dodecad, duodecennial

From duo- +‎ decade.

duodecade (plural duodecades)

1. (nonstandard) A period of two decades, a period of 20 years.
   • 1996, Mary Lindemann, Health & Healing in Eighteenth-century Germany, →ISBN:

     When I divide the past sixty years, 1706-65, into twenty-year periods, [I discover that] in the first duodecade, 702 people died, that is, an average of 35 a year. In the second period to 1745, 850, or 42i/$ each year, perished.

   • 1999, Reformation:

     McIntosh sampled four to six consecutive Leet Court sessions, usually covering two to three years, in each twenty-year span or 'duodecade' of her period. Her f1gures therefore provide a minimum number of communities involved ...

duōdecade

1. ablative singular of duōdecas