Definition of headstock:
(n) :
The part of a lute-type string instrument, such as a guitar, that holds the tuning pegs or tensioning screws of the strings.
(n) :
A part of a machine (such as a lathe or drill) that contains the primary spindle.
(n) :
(mining) A headframe.
(n) :
(rail transport) A transverse structural member at the extreme end of a rail vehicle's underframe, also used on some bogies.
(n) :
A beam that supports a bell.
(n) :
A clamp that restrains a cow by the neck.