roun·del
noun/ˈraʊndl/
/ˈraʊndl/
(specialist)- a round design that is used as a decoration or to identify an aircraft
圆形图案（或标志）；（飞机的）圆形识别标志 Word OriginMiddle English: from Old French rondel, from ro(u)nd-, from a variant of Latin rotundus ‘rotund’.