interlock

(ĭnˌtər-lŏkˈ)

1. To unite or join closely as by hooking or dovetailing.
2. To connect together (parts of a mechanism, for example) so that the individual parts affect each other in motion or operation.

1. A mechanical device that prevents a component from functioning when another component is functioning or situated in a particular way.
2. A stretchy fabric knitted with interlocking stitches by alternating sets of needles on a circular knitting machine.