The Collaborative International Dictionary
poppet head
Headstock \Head"stock`\ (-st[o^]k`), n. (Mach.) A part (usually separate from the bed or frame) for supporting some of the principal working parts of a machine; as:
The part of a lathe that holds the revolving spindle and its attachments; -- also called poppet head, the opposite corresponding part being called a tailstock.
The part of a planing machine that supports the cutter, etc.