decennary

Etymology 1
From +.

Adjective

 * 1) Decennial: of or related to a ten-year period.

Noun

 * 1) A decennium: a period of ten years.

Usage notes
Although may be taken as any group of ten years, it is commonly restricted to the informal ten-year periods of the calendar whose last digits run from 0 to 9. Decennary &c. has no such restriction.

Synonyms

 * See decennium

Etymology 2
From Medieval, a variant of.

Adjective

 * : of or related to the number ten; containing ten items.

Etymology 3
From Medieval, a variant of.

Adjective

 * : of or related to a tithing.

Noun

 * : a tithing.