The word 'mistakenly-cancelled' is a compound word formed from 'mistakenly' and 'cancelled'. 'Mistakenly' originates from the word 'mistake', which comes from Old Norse 'mistaka', meaning 'to take in error'. 'Cancelled' comes from Latin 'cancellare', meaning 'to cross out'.

'Mistakenly' evolved from Middle English 'mistaken', while 'cancelled' evolved from Old French 'canceller'.

Initially, 'mistakenly' meant 'in error', and 'cancelled' meant 'crossed out'. Together, they mean 'cancelled in error'.