powerlessness vs impotency

powerlessness and impotency both are nouns.

Word	Noun	Adjective	Verb	Adverb
powerlessness	Yes	No	No	No
impotency	Yes	No	No	No

As nouns, powerlessness and impotency are synonyms defined as:

powerlessness and impotency: the quality of lacking strength or power; being weak and feeble

Other synonyms of powerlessness include impotence.

powerlessness (noun)	impotency (noun)
the quality of lacking strength or power; being weak and feeble	the quality of lacking strength or power; being weak and feeble
	an inability (usually of the male animal) to copulate