octennial

[Latin octennis eight years old; octennium a period of eight years: octo- = eight, and ann us =a year.] 1. Happening or recurring every eighth year. 2. Lasting eight years. oc-ten-ni-al-ly, adv. [English octennial; -ly.] Once in eight years. foc-tět, s. [Lat. octo eight.] Music: A musical composition for eight parts. oc-tile, s. [Lat. octo eight.] Astron.: The same as OCTANT (q. v.).