noun (n)

• a natural object that covers or envelops(noun.object)

  Example:
  Under a covering of dust.
  

  Synonym:
  cover, natural covering
  

  source: wordnet30
• an artifact that covers something else (usually to protect or shelter or conceal it)(noun.artifact)

  source: wordnet30
• the act of concealing the existence of something by obstructing the view of it(noun.act)

  Synonym:
  cover, masking, screening
  

  source: wordnet30
• the act of protecting something by covering it(noun.act)

  source: wordnet30
• the work of applying something(noun.act)

  Synonym:
  application, coating
  

  source: wordnet30
• Anything which covers or conceals, as a roof, a screen, a wrapper, clothing, etc.(noun)

  source: webster1913