This is the 15964th most frequent Russian word.
прохожий
Passerby.
In this sentence, 'прохожий' refers to someone who is walking by, a pedestrian who happens to be passing by and who was addressed for assistance.
Я обратился к прохожему за помощью, так как потерялся в незнакомом городе.
I asked a passerby for help because I was lost in an unfamiliar city.
Here, 'прохожий' signifies a person who, while passing by, observed a situation that required attention and acted upon it.
Прохожий заметил кошку на дереве и вызвал спасателей.
A passerby noticed a cat in a tree and called rescuers.
In this example, 'прохожий' describes a person encountered sporadically, suggesting infrequent pedestrian presence in the context.