octant

American  

[ok-tuhnt] / ˈɒk tənt /

noun

1. the eighth part of a circle.

2. Mathematics. 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. Astronomy. Octant, the constellation Octans.

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octant British  

/ ˈɒktənt /

noun

1. maths

   1. any of the eight parts into which the three planes containing the Cartesian coordinate axes divide space

   2. an eighth part of a circle

2. astronomy the position of a celestial body when it is at an angular distance of 45° from another body

3. an instrument used for measuring angles, similar to a sextant but having a graduated arc of 45°

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Other Word Forms

• octantal
  adjective

Etymology

Origin of octant

First recorded in 1680–90; from Latin octant- (stem of octāns ); see Octans

Example Sentences

I take my Octant with me also, this I confide La Page.

From The Journals of Lewis and Clark, 1804-1806 by Lewis, Meriwether