a fabric case filled with deformable or resilient material, used for sleeping on 褥垫,床垫 ■(Engineering)a flat structure of brushwood, concrete, or other material used as strengthening or support for foundations, embankments, etc (工程)垫层;沉排;钢筋网
语源
Middle English: via Old French and Italian from Arabic matṛaḥ 'carpet or cushion', from tạrahạ 'to throw'