sterility vs impotence

sterility and impotence both are nouns.

Word	Noun	Adjective	Verb	Adverb
sterility	Yes	No	No	No
impotence	Yes	No	No	No

As nouns, impotence is a hyponym of sterility; that is, impotence is a word with a more specific, narrower meaning than sterility:

sterility: the state of being unable to produce offspring; in a woman it is an inability to conceive; in a man it is an inability to impregnate
impotence: an inability (usually of the male animal) to copulate

Other hyponyms of sterility include impotency, barrenness, cacogenesis, dysgenesis.

sterility (noun)	impotence (noun)
the state of being unable to produce offspring; in a woman it is an inability to conceive; in a man it is an inability to impregnate	the quality of lacking strength or power; being weak and feeble
(of non-living objects) the state of being free of pathogenic organisms	an inability (usually of the male animal) to copulate