Definitions

1. adjective

divided or consisting of eight parts; having eight as the base or radix; of or pertaining to a base of eight.

“The octonary system was used in ancient mathematics.”

2. noun

a number or quantity consisting of eight units or parts.

“He calculated the octonary sum of the numbers.”

3. noun

a musical composition having eight parts or voices.

“The choir performed the complex octonary composition.”