'sanctification' originates from Latin, specifically the word 'sanctificatio', where 'sanctus' meant 'holy' and the root related to 'facere' (as 'fic-') meant 'to make'.

'sanctification' came into English via Late Latin 'sanctificatio' and Medieval Latin, passing through Middle English forms such as 'sanctificacioun' before becoming the modern English 'sanctification'.

Initially, it meant 'the act of making holy or consecrating'; over time it has retained that core meaning but has also come to denote a theological process (progressive moral/spiritual transformation) in religious contexts.