adverb (r)

• in single file(adv.all)

  Example:
  The prisoners came out one by one.
  

  source: wordnet30
• one piece at a time(adv.all)

  source: wordnet30
• apart from others(adv.all)

  Synonym:
  independently, individually, on an individual basis, separately, severally, severally, singly
  

  source: wordnet30