(n)support consisting of the movable part of a lathe that slides along the bed in alignment with the headstock and is locked into position to support the free end of the workpiece
The Collaborative International Dictionary of English (GCIDE) v.0.53Collaborative International Dictionary (GCIDE)
n. The sliding block or support, in a lathe, which carries the dead spindle, or adjustable center. The headstock supports the live spindle. [ 1913 Webster ]