'immature' originates from Latin, specifically the word 'immaturus,' where 'im-' meant 'not' and 'maturus' meant 'ripe or mature.'

'immaturus' transformed into the Old French word 'immature,' and eventually became the modern English word 'immature' through Middle English.

Initially, it meant 'not ripe or mature,' and this meaning has largely remained the same in modern usage.