noun (n)

• (dentistry) dental appliance consisting of an artificial crown for a broken or decayed tooth(noun.artifact)

  Synonym:
  cap, crown, jacket, jacket crown
  

  source: wordnet30
• A work consisting of two or more bastioned fronts, with their outworks, covering an enceinte, a bridgehead, etc., and connected by wings with the main work or the river bank.(noun)

  source: webster1913