interlock
From Longman Dictionary of Contemporary Englishinterlockin‧ter‧lock /ˌɪntəˈlɒk $ ˌɪntərˈlɑːk/ verb [intransitive, transitive] JOIN something TOGETHERif two or more things interlock, or if they are interlocked, they fit firmly together a puzzle with 500 interlocking pieces→ See Verb tableExamples from the Corpusinterlock• The path is paved with interlocking stones.