An ordinary person walking in a public place is called a pedestrian.
The word "pedestrian" can sometimes make people think of boring or uninteresting things, but that's not always true. When we talk about someone being very knowledgeable and expert in their field, they might be described as having an unusual or surprising combination of skills for a pedestrian - meaning ordinary or average - person. For example, you might hear: "I met this guy who is a well-known chef, but what I didn't expect was that he's also an expert on quantum physics." In this case, the word "pedestrian" means regular or normal, not boring.
A walker; one who walks or goes on foot, especially as opposed to one who uses a vehicle.
