1. to connect or fit together firmly by overlapping or hooking together
2. to become connected or joined together

1. a device or mechanism that connects things together
2. the state of being connected or joined together

Examples

• The puzzle pieces interlock perfectly.
• Make sure the safety mechanisms interlock before starting the machine.
• The gears interlock to transfer power from the engine.
• The building blocks are designed to interlock securely.
• The interlock prevents the door from opening while the machine is running.
• There’s a complex interlock between the various computer systems.
• The fence panels have a tight interlock at each joint.