a magnet in the shape of a bar whose magnetic force is strongest at its poles (= ends), one end attracting iron and steel objects and the other end pushing them away

If you hang a bar magnet from a piece of string, its north pole will swing round to point to Earth's North Pole. 如果把一块条形磁铁挂在一根绳子上，它的北极就会旋转指向地球的北极。