This is the 5114th most frequent Arabic word.
الوسطى
"الوسطى" means "the middle" or "the central" in English.
Here, 'الوسطى' is used as an adjective to describe a specific region ('المنطقة'), emphasized as being centrally located.
توجد حديقة كبيرة في المنطقة الوسطى من المدينة.
There is a large park in the middle region of the city.
'الوسطى' in this sentence is used to describe the position of the girl in relation to her sisters, indicating she is neither the eldest nor the youngest.
الفتاة الوسطى بين الأخوات هي الأكثر مرحًا.
The middle girl among the sisters is the most cheerful.
Here, 'الوسطى' is used to identify a middle part, in this case, a part of the hand, emphasizing its functional importance.