adverb (r)

• to an immeasurable degree; beyond measurement(adv.all)

  Example:
  The war left him immeasurably fearful of what man can do to man.
  

  Antonym:
  measurably
  

  source: wordnet30
• without bounds(adv.all)

  Synonym:
  boundlessly, infinitely
  

  source: wordnet30
• In an immeasurable manner or degree.(adverb)

  source: webster1913