1An arc of a circle equal to one eighth of its circumference, or the area enclosed by such an arc with two radii of the circle.
- ‘Included in those downloads are the last two octants needed to complete the color, 360-degree ‘mission success' panorama.’
- ‘The arc was extended from an octant to a sextant and a stout handle was added at the back of the instrument.’
- 1.1 Each of eight parts into which a space or solid body is divided by three planes which intersect (especially at right angles) at a single point.
- ‘The model put forward for the action of BDL suggests that auxin is involved in determining hypophyseal cell fate at the octant stage.’
- ‘At the octant (eight-cell) stage the embryo proper and suspensor are clearly distinct.’
- 1.2 An obsolete instrument in the form of a graduated eighth of a circle, used in astronomy and navigation.
- ‘Instead of compasses, octants, and two-pole chains, modern digital GPS units determine position and direction.’
- ‘Clark used celestial observation to determine latitude, triangulating position with an octant.’
Late 17th century: from Latin octans, octant- ‘half-quadrant’, from octo ‘eight’.
We take a look at several popular, though confusing, punctuation marks.