pedestrian
A person who is walking, especially along streets or roads.
Pedestrian means someone who travels on foot. When you walk to school, cross the street, or stroll through a park, you're a pedestrian. Cities design sidewalks, crosswalks, and traffic signals specifically to keep pedestrians safe from cars and bikes.
For most of human history, nearly everyone was a pedestrian most of the time. Even today, whether you're walking to catch a bus, heading into a store from a parking lot, or hiking a trail, you become a pedestrian the moment you step out and start walking.
Interestingly, pedestrian also means ordinary, dull, or uninspired. If a teacher calls your essay pedestrian, she means it's bland and predictable, like everyone else's. A pedestrian solution to a problem works but shows no creativity or spark. This second meaning suggests something that plods along on foot rather than soaring: functional but forgettable. When someone describes a movie as pedestrian, they're saying it's boring and unremarkable, nothing special worth remembering.
The contrast between these meanings is striking. The same word describes both the simple act of walking and something disappointingly ordinary.