de·cen·ni·al 
(dĭ-sĕnē-əl)
(dĭ-sĕnē-əl)adj.
1. Relating to or lasting for ten years.
2. Occurring every ten years.
n.
A tenth anniversary.
[From Latin decennium, a period of ten years; see DECENNIUM.]
de·cenni·al·ly adv.
- Grand Canal
- Grand Canary
- Grand Canyon
- Grand Cayman
- grandchild
- Grand Coulee
- granddad
- granddaddy
- granddaughter
- grand duchess
- grand duchy
- grand duke
- Grande
- Grande
- grande dame
- grandee
- Grande-Terre
- grandeur
- grandfather
- grandfather clause
- grandfather clock
- grandfatherly
- grandfather paradox
- Grand Forks
- Grand Guignol