dĕcennālis — Lewis & Short
dĕcennālis, e, adj.decem-annus,
I of ten years, decennial (late Lat.; cf.
decennis): bellum, i. e. Caesar's in Gaul,Amm. 15, 12, 6;
of the Trojan war,Hier. adv. Jovin. 1, 48.—
II Subst.: DECENNALIA (ium, n.), a festival celebrated every ten years after the time of Augustus, Trebell. Gallien. 21, 5; Inscr. Grut. 116, 4; v. decennis fin.