The Collaborative International Dictionary of English v.0.48:

Striction \Stric"tion\, n. [L. strictio. See Stringent.]
   The act of constricting, or the state of being constricted.
   [1913 Webster]

   Line of striction (Geom.), the line on a skew surface that
      cuts each generator in that point of it that is nearest to
      the succeeding generator.
      [1913 Webster]