interlock
verbUK /ˌɪntəˈlɒk/
US /ˌɪntərˈlɑːk/
When two things interlock, they fit together like puzzle pieces.
The two rings interlock to make a chain.
OTHER MEANINGS
2. To join or connect parts so that they hold each other in place.
The safety mechanism interlocks the door when the machine is running.
3. A device or arrangement that prevents parts from moving unless certain conditions are met.
The car has an interlock that stops it from starting unless the seatbelt is fastened.
4. To cross or weave together, as fingers or branches.
She interlocks her fingers when she is thinking.