noun (n)

• a member of the Religious Society of Friends founded by George Fox (the Friends have never called themselves Quakers)(noun.person)

  Synonym:
  friend
  

  source: wordnet30
• one who quakes and trembles with (or as with) fear(noun.person)

  Synonym:
  trembler
  

  source: wordnet30
• One who quakes.(noun)

  source: webster1913