'humanise' originates from Latin, specifically the word 'humanus', where 'humanus' meant 'human, humane'; the verb-forming suffix comes via Old French '-iser' / New French '-iser' (and the English suffix '-ize' from Greek '-izein' through Latin and French).

'humanus' passed into Late Latin as 'humanizare' and into Old/Middle French as 'humaniser'; from French it entered English as 'humanize/humanise' and became established in modern English as 'humanise' (British) and 'humanize' (US).

Initially it meant 'to make human or to treat as human'; over time the sense broadened to include 'to make humane' (improve kindness/compassion) and 'to adapt for human use' (apply human-centred design).