archivolt
[ˈɑːkɪvəʊlt]noun
a band of mouldings round the lower curve of an arch
拱门缘饰
■the lower curve itself from impost to impost of the columns
拱墩缘饰
语源mid 17th cent.: from French archivolte or Italian archivolto, based on Latin arcus 'bow, arch' + volvere 'to roll'