Incubi, also known as male demons, are supernatural creatures that have been featured extensively in popular culture. However, there are other words that can be used as synonyms for incubi, including nightmare, ghost, demon, and evil spirit. Additionally, the term "succubus" can also be considered a synonym for the incubus, although it refers specifically to a female demon. Other related words that can be used as synonyms for the incubus include "specter" and "phantasm," which both refer to ghostly or otherworldly entities. It is important to note that the use of different synonyms for the incubus can depend on the cultural or religious context in which they are used.