noun (n)

• the quality of lacking strength or power; being weak and feeble(noun.attribute)

  Synonym:
  impotency, powerlessness
  Antonym:
  power, powerfulness
  

  source: wordnet30
• an inability (usually of the male animal) to copulate(noun.state)

  Synonym:
  impotency
  Antonym:
  potence, potency
  

  source: wordnet30
• The quality or condition of being impotent; want of strength or power, animal, intellectual, or moral; weakness; feebleness; inability; imbecility.(noun)

  source: webster1913