mezzanine

noun
1
a floor that is built between two floors of a building and is smaller than the other floors
نیم‌طبقه, میان‌طبقه
2
the first area of seats above the ground floor in a theatre; the first few rows of these seats
بالکن نخست, طبقه میانی, نیم‌طبقه
see also dress circle