[mass noun]a downy substance obtained from the dried leaves of an Asian plant related to mugwort. It is burnt on or near the skin in Eastern medicine as a counterirritant (针灸用)艾绒,灼烙剂
The plant is Crossostephium artemisioides, family Compositae 该物质来自植物艾,菊科
语源
late 17th cent.: from Japanese mogusa, from moe kusa 'burning herb'