sexennial
adjective
sex·en·ni·al
(ˈ)sek¦senēəl
1
: continuing or lasting six years
a sexennial period
2
: occurring, appearing, or being made, done, or acted upon every six years
sexennially adverb
-əlē
-li
Word History
Etymology
Latin sexennium period of six years (from sex six + -ennium, from annus year) + English -al