
Spectre
Mysterious Presence
Use 'spectre' to describe an eerie, mysterious presence that may cause fear or discomfort. 
Literary Device
'Spectre' is often used in literature to create an unsettling atmosphere or to symbolize hidden fears. 
Not Always Literal
While 'spectre' can mean a ghost, it doesn't always refer to an actual spirit. It may just symbolize something spooky. 