(n.) A flight of stairs with their supporting framework, casing, balusters, etc.

back door back road back street back way bolt-hole by-lane bypass bypath byroad bystreet byway companion companionway covert way detour escalier escalier derobe escape hatch escape route fire escape flight of steps incline landing landing stage perron ramp roundabout way secret exit secret passage secret staircase side door side road side street spiral staircase staircase stairs stairway stepping-stones steps stile treads and risers underground underground railroad underground route