noun (n)

• weakening in force or intensity(noun.event)

  Example:
  Attenuation in the volume of the sound.
  

  Synonym:
  fading
  

  source: wordnet30
• the property of something that has been weakened or reduced in thickness or density(noun.attribute)

  source: wordnet30
• The act or process of making slender, or the state of being slender; emaciation.(noun)

  source: webster1913