3. A surface or line of separation where a division occurs.

4. (Founding)

Defn: The surface of the sand of one section of a mold where it meets that of another section.

5. (Chem.)

Defn: The separation and determination of alloys; esp., the separation, as by acids, of gold from silver in the assay button.

6. (Geol.)

Defn: A joint or fissure, as in a coal seam.

7. (Naut.)

Defn: The breaking, as of a cable, by violence.

8. (Min.)