Definition of "Interlock" :
noun: the act of interlocking or meshing
"An interlocking of arms by the police held the crowd in check."
noun: a device that prevents an automotive engine from starting
"Car theives know how to bypass the ignition interlock."
verb: coordinate in such a way that all parts work together effectively
verb: become engaged or intermeshed with one another
verb: hold in a locking position