Sexennial
Pronunciation : Sex*en"ni*al
Part of Speech : a.
Etymology : [L. sexennium a period of six years, sexennis of six years; sex six + annus a year. See Six, and Annual.]
Definition : Defn: Lasting six years, or happening once in six years. -- n.
Defn: A sexennial event.
Source : Webster's Unabridged Dictionary, 1913