An Etymological Dictionary of Astronomy and Astrophysics

Consisting of twelve → years.

Etymology (EN): From L. duodecennium, from duodecim “tweleve,” from duo, → two, + decem, → ten, + annus “year,” → annual.

Etymology (PE): Davâzdahsâli, from davâzdah “twelve,” from do,
→ two, + dah, → ten + sâl, → year.