a square board with a handle underneath; used by masons to hold or carry mortar
an academic cap with a flat square with a tassel on top
例句
Chinese painting and the piano were the part of her dowry representing culture, equivalent to the college diploma (in a varnished wood frame) and the photograph in mortarboard (sixteen-inch color print in a painted wood frame) of other women. 中国画和钢琴是她嫁妆里代表文化的部分，好比其它女人的大学毕业文凭（配乌油木镜框）和学士帽照相（十六寸彩色配金漆乌油木镜框）。
