Parting

n.
  1. The act of parting or dividing; the state of being parted; division; separation.
  2. A separation; a leave-taking.
  3. A surface or line of separation where a division occurs.
  4. (Founding) The surface of the sand of one section of a mold where it meets that of another section.
  5. (Chem.) The separation and determination of alloys; esp., the separation, as by acids, of gold from silver in the assay button.
  6. (Geol.) A joint or fissure, as in a coal seam.
  7. (Naut.) The breaking, as of a cable, by violence.
  8. (Min.) Lamellar separation in a crystallized mineral, due to some other cause than cleavage, as to the presence of twinning lamellæ.