'eleventh' originates from Old English, specifically the word 'endleofan,' where 'end-' meant 'one' and 'leofan' meant 'left over.'

'endleofan' transformed into the Middle English word 'elleveth,' and eventually became the modern English word 'eleventh.'

Initially, it meant 'one left over after ten,' and this meaning has largely remained the same in modern usage.