This is the 16600th most frequent Russian word.
седьмой
"Seventh."
In this sentence, "седьмой" is used as an ordinal number referring to the sequence order of days in a week.
Сегодня седьмой день недели.
Today is the seventh day of the week.
"Седьмой" here is used to indicate the location by ordinal sequence, specifically the seventh floor in a building.
На седьмом этаже открыли новое кафе.
A new café has been opened on the seventh floor.
In this example, "седьмой" denotes an educational level by order, representing the seventh year in a student's schooling journey.