jack-o'-lantern vs ignis fatuus

jack-o'-lantern and ignis fatuus both are nouns.

Word	Noun	Adjective	Verb	Adverb
jack-o'-lantern	Yes	No	No	No
ignis fatuus	Yes	No	No	No

As nouns, jack-o'-lantern and ignis fatuus are synonyms defined as:

jack-o'-lantern and ignis fatuus: a pale light sometimes seen at night over marshy ground

Other synonyms of jack-o'-lantern include friar's lantern, will-o'-the-wisp.

jack-o'-lantern (noun)	ignis fatuus (noun)
lantern carved from a pumpkin	an illusion that misleads
a pale light sometimes seen at night over marshy ground	a pale light sometimes seen at night over marshy ground