— octantal /ok tan"tl/ , adj.
/ok"teuhnt/ , n.
1. the eighth part of a circle.
2. Math. any of the eight parts into which three mutually perpendicular planes divide space.
3. an instrument having an arc of 24°, used by navigators for measuring angles up to 90°.
4. the position of one heavenly body when 45° distant from another.
5. ( cap. ) Astron. the constellation Octans.
[ 1680-90; octant- (s. of octans ); see OCTANS ]