adverb (r)

• in fear,(adv.all)

  Example:
  She hurried down the stairs fearfully.
  

  Antonym:
  dauntlessly, fearlessly, intrepidly
  

  source: wordnet30
• in an alarming manner(adv.all)

  Example:
  They were fearfully attacked.
  

  Synonym:
  alarmingly, frighteningly, scarily
  

  source: wordnet30
• In a fearful manner.(adverb)

  source: webster1913