'illiterate' originates from Latin, specifically the word 'illiteratus,' where 'in-' meant 'not' and 'litteratus' meant 'lettered or educated.'

'illiteratus' transformed into the Old French word 'illiteré,' and eventually became the modern English word 'illiterate' through Middle English.

Initially, it meant 'unlettered or uneducated,' and this meaning has largely remained the same in modern usage.