'quadrilateral' originates from Latin, specifically the word 'quadrilaterus,' where 'quadri-' meant 'four' and 'laterus' meant 'side.'

'quadrilaterus' transformed into the French word 'quadrilatère,' and eventually became the modern English word 'quadrilateral' through Middle English.

Initially, it meant 'four-sided,' and this meaning has largely remained the same in modern usage.