名词机头; 楼梯每一级的前缘，保护此处的金属板

1. 级面突缘：normal means of egress 正常出路 | nosing 级面突缘 | nosing tile 梯级边缘砖;级咀瓷砖

2. 梯级突边：noser 强迎面风 | nosing 梯级突边 | not water carriage toilet facility 非水冲厕

3. 艏鼻缘：故障灯 not under command light | 艏鼻缘 nosing | 鼻尾线 nose-tail line