noun (n)

• the quality of being valid and rigorous(noun.attribute)

  Synonym:
  cogency, rigor, rigour
  

  source: wordnet30
• the quality of having legal force or effectiveness(noun.attribute)

  Synonym:
  validness
  

  source: wordnet30
• the property of being strong and healthy in constitution(noun.attribute)

  Synonym:
  hardiness, lustiness, robustness
  

  source: wordnet30
• The quality or state of being valid; strength; force; especially, power to convince; justness; soundness; as, the validity of an argument or proof; the validity of an objection.(noun)

  source: webster1913