'irretrievably' originates from the Latin word 'retrievabilis', where 're-' meant 'again' and 'trouvare' meant 'to find'.

'retrievabilis' transformed into the Old French word 'retrouver', and eventually became the modern English word 'retrieve', with 'irretrievably' as its adverbial form.

Initially, it meant 'able to be found again', but over time it evolved into its current meaning of 'in a manner that cannot be recovered'.