jaywalker
A person who crosses a street illegally or carelessly.
A jaywalker is someone who crosses a street in an illegal or careless way, like walking in the middle of a block instead of at a crosswalk, or crossing against a red light. The word comes from an old slang term where “jay” meant a foolish or unsophisticated person, someone who didn't know how to act properly in the city.
When cities first got busy with cars in the early 1900s, people started using the term jaywalker to describe pedestrians who crossed streets carelessly. Before cars dominated roads, people walked wherever they wanted. As traffic increased, cities created rules about where and when people could cross, and jaywalking became the name for breaking those rules.
Today, jaywalking laws vary by location. In some cities, police rarely enforce them. In others, you can get a ticket for crossing outside a crosswalk. The real danger isn't the fine: jaywalking puts you at serious risk of being hit by a car. Drivers don't expect pedestrians to suddenly appear in the middle of the street, so they can't react in time.