ignition lock

English Thesaurus

1. a restraint incorporated into the ignition switch to prevent the use of a vehicle by persons who do not have the key (noun.artifact)

hypernym	:	constraint, restraint,
definition	:	a device that retards something's motion (noun.artifact)

part meronym	:	ignition switch,
definition	:	switch that operates a solenoid that closes a circuit to operate the starter (noun.artifact)