'decalogue' originates from Greek via Late Latin and Medieval Latin, specifically from Greek 'dekalógos' where 'deka-' meant 'ten' and 'lógos' meant 'word' or 'statement'.

'dekalógos' passed into Late Latin as 'decalogus' and then into Middle English/Medieval English as 'decalog'/'decalogue', becoming the modern English word 'decalogue'.

Initially it meant 'ten words' (a literal reference to the Ten Commandments); over time it came to be used more broadly for any authoritative set of ten rules or, by extension, any concise list of fundamental principles.