adverb (r)

• in accordance with truth or fact or reality(adv.all)

  Example:
  She was now truly American.
  

  Synonym:
  genuinely, really
  

  source: wordnet30
• by right(adv.all)

  Synonym:
  rightfully
  

  source: wordnet30
• with sincerity; without pretense(adv.all)

  Example:
  We are truly sorry for the inconvenience.
  

  Synonym:
  sincerely, unfeignedly
  Antonym:
  insincerely
  

  source: wordnet30
• in fact (used as intensifiers or sentence modifiers)(adv.all)

  Example:
  A truly awful book.
  

  Synonym:
  in truth, really
  

  source: wordnet30
• In a true manner; according to truth; in agreement with fact; as, to state things truly; the facts are truly represented.(adverb)

  source: webster1913