If you are not single, but dream that you are, suggests that you need to stand up for yourself and be strong. You need to approach a situation or matter on your own and not lean on others. Alternatively, the dream may be a metaphor that you are being "singled" out or being picked on.
For married persons to dream that they are single, foretells that their union will not be harmonious, and constant despondency will confront them.