'adequate' originates from Latin, specifically the word 'adaequatus,' where 'ad-' meant 'to' and 'aequus' meant 'equal.'

'adaequatus' transformed into the French word 'adéquat,' and eventually became the modern English word 'adequate' through Middle English.

Initially, it meant 'equal to or sufficient for a purpose,' and this meaning has largely remained the same in modern usage.