'modernise' originates from French, specifically the word 'moderniser', where the element 'modern-' ultimately comes from Latin 'modernus' (from 'modo' meaning 'just now' or 'recent').

'moderniser' developed from post-classical Latin/Medieval Latin formations (e.g. 'modernizare') and the English verb was formed in the 17th century by combining 'modern' with the verbalizing suffix (compare French '-iser' / English '-ize/-ise'), eventually arriving at the English form 'modernise'.

Initially it meant 'to make modern' or 'to render recent,' and over time this core meaning has remained but broadened to include updating technology, systems, language, laws, and fashions to contemporary standards.