'steadfastly-focused' originates from the combination of 'steadfastly' and 'focused'. 'Steadfastly' comes from Old English 'stedefæst', where 'stede' meant 'place' and 'fæst' meant 'firm'. 'Focused' comes from Latin 'focus', meaning 'hearth' or 'fireplace', which evolved to mean 'center of activity or interest'.

'Steadfastly' changed from Old English 'stedefæst' to Middle English 'stedfast', and eventually became the modern English 'steadfastly'. 'Focus' transformed from Latin 'focus' to the modern English 'focus'.

Initially, 'steadfastly' meant 'firmly fixed in place', but over time it evolved to mean 'firmly determined'. 'Focus' originally referred to a 'hearth', but now it means 'center of interest or activity'.