noun (n)

• poor physical condition; being out of shape or out of condition (as from a life of ease and luxury)(noun.state)

  Synonym:
  softness
  Antonym:
  fitness, physical fitness
  

  source: wordnet30
• lacking the power to perform(noun.attribute)

  Synonym:
  inability
  Antonym:
  ability
  

  source: wordnet30
• the quality of not being suitable(noun.attribute)

  Example:
  The judges agreed on his unfitness for the appointment.
  

  Antonym:
  fitness, fittingness
  

  source: wordnet30