Quadrant

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

  Quadrant \Quad"rant\, n. [L. quadrans, -antis, a fourth part, a
     fourth of a whole, fr. quattuor four: cf. F. quadrant,
     cadran. See {Four}, and cf. {Cadrans}.]
     1. The fourth part; the quarter. [Obs.] --Sir T. Browne.
        [1913 Webster]
  
     2. (Geom.) The quarter of a circle, or of the circumference
        of a circle, an arc of 90[deg], or one subtending a right
        angle at the center.
        [1913 Webster]
  
     3. (Anal. (Geom.) One of the four parts into which a plane is
        divided by the coordinate axes. The upper right-hand part
        is the first quadrant; the upper left-hand part the
        second; the lower left-hand part the third; and the lower
        right-hand part the fourth quadrant.
        [1913 Webster]
  
     4. An instrument for measuring altitudes, variously
        constructed and mounted for different specific uses in
        astronomy, surveying, gunnery, etc., consisting commonly
        of a graduated arc of 90[deg], with an index or vernier,
        and either plain or telescopic sights, and usually having
        a plumb line or spirit level for fixing the vertical or
        horizontal direction.
        [1913 Webster]
  
     {Gunner's quadrant}, an instrument consisting of a graduated
        limb, with a plumb line or spirit level, and an arm by
        which it is applied to a cannon or mortar in adjusting it
        to the elevation required for attaining the desired range.
        
  
     {Gunter's quadrant}. See {Gunter's quadrant}, in the
        Vocabulary.
  
     {Hadley's quadrant}, a hand instrument used chiefly at sea to
        measure the altitude of the sun or other celestial body in
        ascertaining the vessel's position. It consists of a frame
        in the form of an octant having a graduated scale upon its
        arc, and an index arm, or alidade pivoted at its apex.
        Mirrors, called the index glass and the horizon glass, are
        fixed one upon the index arm and the other upon one side
        of the frame, respectively. When the instrument is held
        upright, the index arm may be swung so that the index
        glass will reflect an image of the sun upon the horizon
        glass, and when the reflected image of the sun coincides,
        to the observer's eye, with the horizon as seen directly
        through an opening at the side of the horizon glass, the
        index shows the sun's altitude upon the scale; -- more
        properly, but less commonly, called an octant.
  
     {Quadrant of altitude}, an appendage of the artificial globe,
        consisting of a slip of brass of the length of a quadrant
        of one of the great circles of the globe, and graduated.
        It may be fitted to the meridian, and being movable round
        to all points of the horizon, serves as a scale in
        measuring altitudes, azimuths, etc.
        [1913 Webster]

From WordNet (r) 2.0 [wn]:

  quadrant
       n 1: a quarter of the circumference of a circle [syn: {right
            angle}]
       2: a quarter of the circumference of a circle [syn: {quarter-circle}]
       3: any of the four areas into which a plane is divided by two
          orthogonal coordinate axes
       4: the area enclosed by two perpendicular radii of a circle
       5: a measuring instrument for measuring altitude of heavenly
          bodies

From Moby Thesaurus II by Grady Ward, 1.0 [moby-thes]:

  51 Moby Thesaurus words for "quadrant":
     adjunct, astrolabe, azimuth circle, azimuth compass, bevel,
     bevel protractor, bevel square, clinometer, component, contingent,
     crescent, cross section, detachment, detail, division, dole,
     fraction, goniometer, graphometer, half circle, hemicycle,
     installment, item, pantometer, parcel, part, particular,
     percentage, portion, protractor, quarter, quota, radiogoniometer,
     random sample, remainder, sample, sampling, section, sector,
     segment, semicircle, sextant, share, subdivision, subgroup,
     subspecies, theodolite, transit, transit circle,
     transit instrument, transit theodolite
  
  

From Bouvier's Law Dictionary, Revised 6th Ed (1856) [bouvier]:

  QUADRANT. In angular measures, a quadrant is equal to ninety degrees. Vide 
  Measure.