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