1. 底面：activate,)皮肤(skin)的现象出现,观察沙发其前后所用面料是否一致;看内部(interior,inside)垫层(filled)质量时下高档(top grade)沙发座(seat)和背(back)的底面(underside)多采用尼龙带(nylon)和蛇簧交叉网编结构,
2. 下面,下侧：undergo 经受 | underside 下面,下侧 | undue 不适当的,过度的
3. 断层底板翼：underseam 下层 | underside 断层底板翼 | undersize 筛下产品
4. 下面：undershrub 小灌木 | underside 下面 | undersign 签名
1. 底面；下面；下侧
The underside of something is the part of it which normally faces towards the ground.
e.g. ...the underside of the car.
车的底部
e.g. ...the underside of the eyelid.
眼睑内侧