'law-related' originates from English, combining the noun 'law' (ultimately from Old Norse 'lagu') and the adjective 'related' (from Latin 'relatus' via Old French and Middle English), where 'lagu' meant 'that which is laid down' and 'relatus' meant 'brought or carried back'.

'law' came into English under Old Norse/Old English influence as 'lagu'/'lag' and developed into modern 'law'; 'related' developed from Latin 'referre' -> past participle 'relatus' through Old French into Middle English; in modern English these elements are combined as the compound 'law-related'.

Initially, 'law' referred to rules laid down and 'related' to the sense of being connected or 'brought back'; over time the compound came to be used adjectivally to mean 'connected with legal matters'.