infinitely vs lengthily

infinitely

adv
  • To a surpassingly large extent. 

  • In an infinite manner; as of anything growing without bounds; endlessly. 

lengthily

adv
  • In a lengthy way, in a manner that is long and drawn out, especially in time. 

How often have the words infinitely and lengthily occurred in a corpus of books? (source: Google Ngram Viewer )