This is the 50th most frequent Indonesian word.
sekitar
"Sekitar" means "around" or "approximately" in English.
In this sentence, 'sekitar' is used as a preposition to indicate an approximate location or area, specifically 'around' the city center.
Saya tinggal di sekitar pusat kota.
I live around the city center.
In this case, 'sekitar' again is a preposition indicating a spatial context of 'around' the park.
Sekitar taman tersebut banyak anak-anak bermain.
Around that park, many children are playing.
Here, 'sekitar' signifies an approximation, functioning as an adverb to quantify 'ten words'.