vanishing line

Vanishing \Van"ish*ing\,
   a. & n. from {Vanish}, v.
   [1913 Webster]

   {Vanishing fraction} (Math.), a fraction which reduces to the
      form 0/0 for a particular value of the variable which
      enters it, usually in consequence of the existence of a
      common factor in both terms of the fraction, which factor
      becomes 0 for this particular value of the variable.
      --Math. Dict.

   {Vanishing line} (Persp.), the intersection of the parallel
      of any original plane and the picture; one of the lines
      converging to the vanishing point.

   {Vanishing point} (Persp.), the point to which all parallel
      lines in the same plane tend in the representation.
      --Gwilt.

   {Vanishing stress} (Phon.), stress of voice upon the closing
      portion of a syllable. --Rush.
      [1913 Webster]