poppet

noun

1. tailstock
2. a valve that moves into and from its seat: often cam-driven and spring-loaded for a rapid repeating, popping action as in a gasoline engine
   in full poppet valve
3. any of certain timbers used to support a ship about to be launched
4. 1. Obsolete a doll
   2. Brit., Informal a term of endearment, as for a child or sweetheart