'amphitheatered' originates from the word 'amphitheater', which comes from the Greek word 'amphitheatron', where 'amphi-' meant 'on both sides' and 'theatron' meant 'place for viewing'.

'amphitheatron' transformed into the Latin word 'amphitheatrum', and eventually became the modern English word 'amphitheater'.

Initially, it meant 'a place for viewing on both sides', but over time it evolved into its current meaning of 'a large, open-air venue with tiered seating'.