'peg-and-socket' originates from English, specifically the words 'peg' and 'socket', where 'peg' meant 'a small cylindrical object' and 'socket' meant 'a hollow part designed to receive a corresponding part'.

'peg' and 'socket' have been used in English since the Middle Ages, and the combination 'peg-and-socket' became a common term in carpentry and mechanical contexts.

Initially, it referred to a simple mechanical connection, and this meaning has largely remained the same in modern usage.