Angular aperture

Angular \An"gu*lar\, a. [L. angularis, fr. angulus angle,
   corner. See {Angle}.]
   1. Relating to an angle or to angles; having an angle or
      angles; forming an angle or corner; sharp-cornered;
      pointed; as, an angular figure.
      [1913 Webster]

   2. Measured by an angle; as, angular distance.
      [1913 Webster]

   3. Fig.: Lean; lank; raw-boned; ungraceful; sharp and stiff
      in character; as, remarkably angular in his habits and
      appearance; an angular female.
      [1913 Webster]

   {Angular aperture}, {Angular distance}. See {Aperture},
      {Distance}.

   {Angular motion}, the motion of a body about a fixed point or
      fixed axis, as of a planet or pendulum. It is equal to the
      angle passed over at the point or axis by a line drawn to
      the body.

   {Angular point}, the point at which the sides of the angle
      meet; the vertex.

   {Angular velocity}, the ratio of anuglar motion to the time
      employed in describing.
      [1913 Webster]