adverb (r)

• as a devil; in an evil manner(adv.all)

  Synonym:
  diabolically, fiendishly
  

  source: wordnet30
• in a playfully devilish manner(adv.all)

  Example:
  The socialists are further handicapped if they believe that capitalists are not only wicked but also devilishly clever.
  

  Synonym:
  devilish
  

  source: wordnet30
• (used as intensives) extremely(adv.all)

  Synonym:
  deadly, deucedly, insanely, madly
  

  source: wordnet30