<p><strong>Verb</strong></p><ul><li>(used without object) to fit into each other, as parts of machinery, so that all action is synchronized.</li><li>to interweave or interlace, one with another: The branches of the trees interlock to form a natural archway.</li><li>(of switches, signals, etc.) to operate together in a prearranged order.</li><li>(used with object) to lock one with another.</li><li>to fit (parts) together to ensure coordinated action.</li><li>to arrange (switches, signals, etc.) to effect a predetermined sequence of movement.</li></ul><p><strong>Noun</strong></p><ul><li>the fact or condition of interlocking or of being interlocked.</li><li>the existence or an instance of an interlocking directorate.</li><li>a device for preventing a mechanism from being set in motion when another mechanism is in such a position that the two operating simultaneously might produce undesirable results.</li><li>a device or system that prevents an automotive engine from starting until the seat belt for any occupied front seat is fastened.</li><li>a stretch fabric made with a circular knitting machine having two alternating sets of long and short needles.</li><li>a device for synchronizing the action of a camera and sound recorder.</li></ul>