upstairs
US /ʌpˈsterz/
UK /ʌpˈsterz/

1.
on or to an upper floor of a building
:
•
She went upstairs to get a book.
•
The children are playing upstairs.
1.
situated on an upper floor of a building
:
•
The upstairs bedroom has a great view.
•
We need to fix the upstairs bathroom.
1.
the upper floor or floors of a building
:
•
The noise is coming from upstairs.
•
She lives in the upstairs of the old house.