The word "phantom" is often used to describe something mysterious or unreal. There are many synonyms for this word that depict the same eerie and ghostly feeling. For instance, "specter", "apparition", "ghost", "wraith", and "shadow" are common synonyms that are often used interchangeably with "phantom". Other synonyms for this word include "spirit", "phantasm", "hallucination", "illusion", and "delusion". These synonyms can be used to describe anything from supernatural entities to illusions and dreams that feel hauntingly real. Whether you're writing a suspenseful novel or simply trying to express a spooky thought, using synonyms for the word "phantom" can help add an extra level of mystique to your language.