quadrilat·eral
noun/ˌkwɒdrɪˈlætərəl/
/ˌkwɑːdrɪˈlætərəl/
(geometry)- a flat shape with four straight sides
Topics Colours and Shapesc2四边形 Word Originmid 17th cent.: from late Latin quadrilaterus (from Latin quadri- ‘four’ + latus, later- ‘side’) + -al.