This means someone who has ran away from home or has been taken away from home, even if this person is an adult, without any indication of where they’d be going to anyone, directly or indirectly. The second is disappearance in the sense of killing oneself or dying, which means to be gone from the world for all intents and purposes but it does not mean to totally disappear because the body cannot ever be totally gone.
If you have a dream in which you disappear then this means that you feel like you haven’t been noticed lately and you need some attention. It might sound a little needy but there is a point in everyone’s life where they just feel like they need to be recognized by someone for something that they’ve done. Maybe you really have done a bang up job on an important project and want someone to acknowledge that. This is perfectly sensible and not at all unwarranted. To dream that you’ve disappeared means you feel like you have been neglected. Disappearing dreams usually come up after one specific event that was particularly traumatizing though, and not just any event.
One of the most important things to interpretation though is to notice how the person felt about disappearing. Did you want to disappear and did you deliberately leave. Since it is a dream you can also force yourself to literally disappear in the more mystical sense of the term where all trace of you is literally gone even though your consciousness remains where it is. If you willed this to happen, or if you took part in leaving town which also counts as a disappearance and you were happy with the results, then this means that you have some desire to disappear. There are a variety of reasons why you might try to erase your existence. The most common one is embarrassment with bullying being a close cousin. Thankfully bullying decreases a lot or at least becomes more complex and less overtly hurtful once you get out of school. The end result though is you feel like leaving everything behind because of how others have hurt you. This is not a healthy attitude to have and if you want to get better, you’re going to have to make a lot of changes to make yourself feel better.
Another reason that you might dream of disappearing has to do with the opposite motivation for the disappearance. It can’t be something that you purposefully wanted to do; it has to be something that was done on accident or something that happened to you against your will. IF this is what happened in your dream then it means that you feel like your actions have not been getting the recognition they’ve deserved recently. You need to go out and make a name for yourself. Show people that you’re worth something and that you matter. You need to let people know that you are important and that there is a reason that you are alive. If you have a dream in which you disappear this is an indication that you don’t feel recognized and a lack of recognition, whether real or perceived means that you will eventually begin to sink into depression and you can’t allow this to happen either.