'unathletic' originates from the prefix 'un-' meaning 'not' and the word 'athletic', which comes from the Greek word 'athlētikos', meaning 'pertaining to contests'.

'athlētikos' transformed into the Latin word 'athleticus', and eventually became the modern English word 'athletic'. The prefix 'un-' was added to form 'unathletic'.

Initially, 'athletic' meant 'pertaining to contests', but over time it evolved to mean 'physically strong and active'. 'Unathletic' negates this meaning.