ˈäktənt noun
( -s )
Etymology: Latin octant-, octans half quadrant, from octo eight
1.
a. : the position or aspect of a celestial body (as the moon or a planet) when halfway between conjunction or opposition and quadrature
b. : an instrument used for observing altitudes of a celestial body from a moving ship or aircraft and having a maximum angle of 45 degrees between its reflecting mirrors — compare sextant
2.
a. : one of the eight regions into which three usually orthogonal planes meeting in a point divide all three-dimensioned space around it
b. : any of the eight parts into which a space is divided by three coordinate planes