noun (n)

• the housing or outer covering of something(noun.artifact)

  Synonym:
  case, shell
  

  source: wordnet30
• the outermost covering of a pneumatic tire(noun.artifact)

  source: wordnet30
• the enclosing frame around a door or window opening(noun.artifact)

  Example:
  The casings had rotted away and had to be replaced.
  

  Synonym:
  case
  

  source: wordnet30
• The act or process of inclosing in, or covering with, a case or thin substance, as plaster, boards, etc.(noun)

  source: webster1913