adverb (r)

• without variation or change, in every case(adv.all)

  Example:
  Constantly kind and gracious.
  

  Synonym:
  always, invariably
  

  source: wordnet30
• without interruption(adv.all)

  Example:
  The world is constantly changing.
  

  Synonym:
  always, forever, incessantly, perpetually, uninterruptedly
  

  source: wordnet30
• With constancy; steadily; continually; perseveringly; without cessation; uniformly.(adverb)

  source: webster1913