abovestairs
ˈæbəvˌsteɪrz
Definitions
1. noun
A set of stairs leading to the upper floors of a building, especially in a large or old house.
“The family lived in the mansion with abovestairs and a grand ballroom.”
2. adverb
Above the stairs, especially in a large or old house.
“The servant was stationed abovestairs, keeping watch over the hallway.”