The Collaborative International Dictionary of English v.0.48:

Quadrantal \Quad*ran"tal\, a. [L. quadrantalis containing the
   fourth fourth part of a measure.] (Geom.)
   Of or pertaining to a quadrant; also, included in the fourth
   part of a circle; as, quadrantal space.
   [1913 Webster]

   Quadrantal triangle, a spherical triangle having one side
      equal to a quadrant or arc of 90[deg].

   Quadrantal versor, a versor that expresses rotation through
      one right angle.
      [1913 Webster]