Octant

2 definitions found

From The Collaborative International Dictionary of English v.0.48 [gcide]:

  Octant \Oc"tant\, n. [L. octans, -antis. fr. octo eight. See
     {Octave}.]
     1. (Geom.) The eighth part of a circle; an arc of 45 degrees.
        [1913 Webster]
  
     2. (Astron. & Astrol.) The position or aspect of a heavenly


        body, as the moon or a planet, when half way between
        conjunction, or opposition, and quadrature, or distant
        from another body 45 degrees.
        [1913 Webster]
  
     3. An instrument for measuring angles (generally called a
        {quadrant}), having an arc which measures up to 9O[deg],
        but being itself the eighth part of a circle. Cf.
        {Sextant}.
        [1913 Webster]
  
     4. (Math. & Crystallog.) One of the eight parts into which a
        space is divided by three coordinate planes.
        [1913 Webster]

From WordNet (r) 2.0 [wn]:

  octant
       n : a measuring instrument for measuring angles to a celestial
           body; similar to a sextant but with 45 degree calibration