Dreaming about crossbones are typically thought to be related to death in real life. In some cases, this symbol suggests that something important could happen to you.
Part of the symbolizing with crossbones is due to the fact that it is often associated with pirates. Thus the dream signifies the dangers of encountering death and diseases at any moment.
Seeing crossbones in a dream may signify paranoia about authority, lack of trust, or guilt. It can also represent a need for self-protection and compassion.