Definition: The word "specter" is a noun that generally means a ghost or a spirit. It can also refer to a haunting memory or thought that troubles someone.
In literature, "specter" can be used metaphorically to discuss fears or anxieties that are not physical but still affect a person's mind. For instance, "The specter of failure loomed over her as she prepared for the big exam."
While "specter" doesn't have specific idioms or phrasal verbs associated with it, you might encounter phrases like "haunted by the past," which conveys a similar idea of being troubled by memories.
"Specter" is a versatile word that refers to both ghostly figures and haunting memories.