'reference' originates from Latin, specifically the Late Latin word 'referentia' (from the verb 'referre'), where 're-' meant 'back' and 'ferre' meant 'to carry'.

'referentia' passed into Old French/Medieval Latin as 'reference'/'référence' and then into Middle English as 'reference', eventually becoming the modern English word 'reference'.

Initially, it meant 'a bringing back' or 'the act of carrying back' (in the sense of reporting or relating); over time it evolved into the senses 'the act of referring' and 'a source or citation' used in modern English.