'adoptee' originates from the English word 'adopt,' which comes from the Latin word 'adoptare,' where 'ad-' meant 'to' and 'optare' meant 'choose.'

'adoptare' transformed into the Old French word 'adopter,' and eventually became the modern English word 'adopt' through Middle English.

Initially, it meant 'to choose for oneself,' but over time it evolved into its current meaning of 'to take as one's own child.'