'misdiagnose' originates from the prefix 'mis-' meaning 'wrongly' and the word 'diagnose' from Greek 'diagnōsis', where 'dia-' meant 'through' and 'gnosis' meant 'knowledge'.

'diagnōsis' transformed into the Latin word 'diagnosis', and eventually became the modern English word 'diagnose'. The prefix 'mis-' was added to form 'misdiagnose'.

Initially, it meant 'to know through examination', but with the prefix 'mis-', it evolved to mean 'to know wrongly through examination'.