Corridor
Hallway
noun
A corridor is below. What do you call a corridor that's below? Well, really it's still just a corridor or hallway.
ろうか
This is a jukugo word, which usually means on'yomi readings from the kanji. If you know the readings of your kanji you'll know how to read this as well.
彼が廊下でバナナの皮に滑るのを見て、彼女は思わず吹き出してしまった。
When she saw him slip on a banana peel in the hallway, she burst out laughing.