This is the 376th most frequent Hebrew word.
השלישי
"The third."
Here, the word 'השלישי' is used as an ordinal adjective to describe the third position of the child in the family.
הילד השלישי במשפחה מקבל צעצוע חדש.
The third child in the family receives a new toy.
Here, 'השלישי' functions as a noun to refer to the person occupying the third position in line.
השלישי בתור נכנס למשרד.
The third in line entered the office.
In this case, 'השלישי' indicates the third item or installment within a sequence, like episodes in a series.