figment vs idea

figment and idea both are nouns.

Word	Noun	Adjective	Verb	Adverb
figment	Yes	No	No	No
idea	Yes	No	No	No

As nouns, idea is a hypernym of figment; that is, idea is a word with a broader meaning than figment:

Other hypernyms of figment include thought.

figment (noun)	idea (noun)
a contrived or fantastic idea	the content of cognition; the main thing you are thinking about
	your intention; what you intend to do
	an approximate calculation of quantity or degree or worth
	a personal view
	(music) melodic subject of a musical composition