'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 fully developed,' but over time it evolved into its current meaning of 'not fully developed or grown.'