1A faint southern constellation (the Octant), containing the south celestial pole.

1. 1.1as genitive Octantis /ɒkˈtantɪs/ Used with preceding letter or numeral to designate a star in the constellation Octans.
   与其前面的字母或数字连用以标记该星座中的星南极星座的
   the star Delta Octantis

   南极座δ星。