Staircase (noun)

1. A set of steps for going up or down, typically inside a building and with a banister.
2. A series of steps or floors in a building or structure.

Origin:

Mid 16th century: from stair + case.

Examples:

1. She walked up the staircase to the second floor.
2. He was looking at the details of the grand staircase.
3. The staircase was made of marble.
4. The staircase was very steep.
5. The staircase was the main feature of the entrance hall.