ignis fatuus vs will-o'-the-wisp

ignis fatuus and will-o'-the-wisp both are nouns.

Word	Noun	Adjective	Verb	Adverb
ignis fatuus	Yes	No	No	No
will-o'-the-wisp	Yes	No	No	No

As nouns, ignis fatuus and will-o'-the-wisp are synonyms defined as:

As nouns, ignis fatuus and will-o'-the-wisp are synonyms defined as:

ignis fatuus and will-o'-the-wisp: a pale light sometimes seen at night over marshy ground

Other synonyms of ignis fatuus include friar's lantern, jack-o'-lantern.

ignis fatuus (noun)	will-o'-the-wisp (noun)
an illusion that misleads	an illusion that misleads
a pale light sometimes seen at night over marshy ground	a pale light sometimes seen at night over marshy ground