What is the meaning of truly?

adverb

• In accordance with truth or fact or reality.
  • usage: "she was now truly American"; "a genuinely open society"; "they don't really listen to us"
  • synonyms: genuinely, really
• By right.
  • usage: "baseball rightfully is the nation's pastime"
  • synonyms: rightfully
• With sincerity; without pretense.
  • usage: "she praised him sincerely for his victory"; "was unfeignedly glad to see his old teacher"; "we are truly sorry for the inconvenience"
  • synonyms: sincerely, unfeignedly
• In fact (used as intensifiers or sentence modifiers. )
  • usage: "in truth, moral decay hastened the decline of the Roman Empire"; "really, you shouldn't have done it"; "a truly awful book"
  • synonyms: in truth, really