noun (n)

• the relative importance granted to something(noun.attribute)

  Example:
  The progression implied an increasing weightiness of the items listed.
  

  Synonym:
  weight
  

  source: wordnet30
• the property of being comparatively great in weight(noun.attribute)

  Synonym:
  heaviness
  Antonym:
  lightness, weightlessness
  

  source: wordnet30
• The quality or state of being weighty; weight; force; importance; impressiveness.(noun)

  source: webster1913