What is "endpin"

n. (context music lutherie English) The spike of a cello or double bass that makes contact with the floor.

The endpin or spike is the component of a cello or double bass that makes contact with the floor to support the instrument's weight. It is made of metal, carbon fiber, or, occasionally, wood, and is extensible from the bottom of the instrument, and secured there with a thumbscrew. Most bass clarinets and contrabassoons also have a similar fixture.