To jaywalk is to cross the street in the middle of the block, rather than in a crosswalk, or in front of oncoming cars that have the right of way. If you dare to jaywalk, you might be violating a pedestrian traffic law. Shame on you.
When you jaywalk, you don't follow the rules of the road that protect pedestrians and drivers. If you dash across the street against a red light, you jaywalk. Likewise, if you meander across a busy road rather than waiting at a crosswalk, you also jaywalk. Jaywalk comes from jay walker, coined in Kansas City in 1906, from the sense of jay as an ignorant person. Jaywalk was first used in Hutchinson, Kansas in 1909.