'accidentally-stored' originates from the combination of 'accidentally' and 'stored', where 'accidentally' comes from Latin 'accidentalis', meaning 'happening by chance', and 'stored' from Old English 'stōrian', meaning 'to keep or place'.

'accidentally' evolved from the Latin 'accidentalis' through Old French 'accidentel', and 'stored' from Old English 'stōrian', eventually forming the modern English compound 'accidentally-stored'.

Initially, 'accidentally' meant 'by chance', and 'stored' meant 'to keep', which together evolved to mean 'kept by chance'.