Jaywalking is the act of walking across a road where it is dangerous or against the rules — for example mid-block, or against the light. In American English it is the normal noun for that act, and in some US cities it is written into the law. British English understands it, but it still sounds a bit American. Though actually, the idea that 'the street is for cars, and walkers must stay in their box' is newer than people think; the word was pushed hard in the early days of cars. In everyday talk it can also be the -ing form of the verb: she was jaywalking. Taiwan has rules about crossing too, but students here more often hear 闖紅燈 or 不走斑馬線 than this English noun.