striction

/S T R IH1 K SH AH0 N/
noun
  1. 1

    The act of constricting, or the state of being constricted.

  2. 2

    (geometry) The definition of a geometric shape as all points with some relationship to a central point, curve, etc., for example, a circle is the striction of all points at a distance of the radius from a single point.