[mass noun]a kind of ferruginous earth used as a pigment in painting, normally yellowish-brown in colour (raw sienna) or deep reddish-brown when roasted (burnt sienna) (富铁)黄土(用作颜料) ■the colour of this pigment 赭色
语源
late 18th cent.: from Italian (terra di) Sienna ('earth of) Siena'