复数:undercoats
1.大衣内的上衣
2.〈口〉(女用)衬裙
3.(动物长毛下面的)浓密的绒毛
4.(涂在车辆底部的)底部防锈层;(上漆之前的)内涂层
1.给...加内涂层
1.the first layer of paint that you put on a surface