What is the meaning of inadequacy?

noun

• Lack of an adequate quantity or number.
  • usage: "the inadequacy of unemployment benefits"
  • synonyms: insufficiency, deficiency
• A lack of competence.
  • usage: "pointed out the insufficiencies in my report"; "juvenile offenses often reflect an inadequacy in the parents"
  • synonyms: insufficiency
• Unsatisfactoriness by virtue of being inadequate.
  • synonyms: inadequateness