[mass noun](Geology)a loosely compacted yellowish-grey deposit of wind-blown sediment of which extensive deposits occur e.g. in eastern China and the American Midwest (地质)(存在于中国东部和美国中西部的沉积)黄土
派生 loessial adjective loessic adjective 语源
mid 19th cent.: from German Löss, from Swiss German lösch 'loose'