noun (n)

• an artful or simulated semblance(noun.attribute)

  Example:
  Under the guise of friendship he betrayed them.
  

  Synonym:
  pretence, pretense, pretext
  

  source: wordnet30
• Customary way of speaking or acting; custom; fashion; manner; behavior; mien; mode; practice; -- often used formerly in such phrases as: at his own guise; that is, in his own fashion, to suit himself.(noun)

  source: webster1913