will-o'-the-wisp

English Thesaurus

1. an illusion that misleads (noun.cognition)

hypernym	:	fancy, fantasy, illusion, phantasy,
definition	:	something many people believe that is false (noun.cognition)

2. a pale light sometimes seen at night over marshy ground (noun.phenomenon)

hypernym	:	light, visible light, visible radiation,
definition	:	(physics) electromagnetic radiation that can produce a visual sensation (noun.phenomenon)