D / dĕcennĭum
noun

dĕcennĭum

gen. dĕcennii · gender neuter · decl. 2nd
A period of ten years
A period of ten years (post-class.), App. de Deo. Socr. p. 52, 7 al.
i. q. decennalia, Trebell. Gallien. 7 fin.
i. q. decennalia, Trebell. Gallien. 7 fin.