forgetfulness vs blackout

forgetfulness and blackout both are nouns.

Word	Noun	Adjective	Verb	Adverb
forgetfulness	Yes	No	No	No
blackout	Yes	No	No	No

As nouns, blackout is a hypernym of forgetfulness; that is, blackout is a word with a broader meaning than forgetfulness:

Other hypernyms of forgetfulness include amnesia, memory loss.

forgetfulness (noun)	blackout (noun)
tendency to forget	a momentary loss of consciousness
unawareness caused by neglectful or heedless failure to remember	partial or total loss of memory
	the failure of electric power for a general region
	darkness resulting from the extinction of lights (as in a city invisible to enemy aircraft)
	a suspension of radio or tv broadcasting