If you are the dead person or the dead person is unknown to you, then some aspect of your personality or some issue in your daily life needs to be left behind.
If a friend dies in your dream, perhaps that friendship has run its course, or perhaps your friend is about to get married and the nature of your friendship will change. [1]
If the sensation associated with this goodbye is unpleasant, it may indicate you are too relaxed in your habits. If, however, you are saying goodbye to another, it is likely that soon you will meet this individual again. The farewell can also be a sign of peace, when you say goodbye to annoying aspects of your life; and a sign of great relief when obstacles that kept you back fall behind you.
According to most traditions, to say goodbye is a sad omen of marital separation and death of a loved one. [2]
A temporary ending or a parting, as in “goodbye for now.” A mock-up or “what if” scenario as played out by your subconscious mind, perhaps providing greater insight into your feelings about the person you’re parting with in the dream.
See also: Leaving a Person, Leaving a Place, Distance, Divider [3]