This is the 13548th most frequent Polish word.
pieszą
"Pieszą" means "pedestrian" (feminine form) in English.
In this sentence, 'pieszą' is used in the instrumental case to refer to a female pedestrian.
Pieszą idzie chodnikiem.
The pedestrian is walking on the sidewalk.
Here, 'pieszą' describes a female pedestrian, reflecting the accusative case in the sentence.
Spotkałem pieszą na rynku.
I met the pedestrian at the marketplace.
In this context, 'pieszą' is in the instrumental case after the preposition 'z,' referring again to a female pedestrian.