If an item in a dream is missing, it most likely represents something in your life or something within you that is missing. Where in your life is there emptiness? If a person is missing, itm ay mean that you “miss” that person. Often, parents will dream their child is missing. This is because the parent and child are growing apart.
Missing a bus, plane, etc. indicates a fear of missing out on opportunity OR can refer to a deadline you face in real life.