lengthily vs momentarily

lengthily

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

momentarily

adv
  • In a momentary manner; for a moment or instant. 

  • Progressively; moment by moment. 

  • In a moment or very soon; any minute now, any time now. 

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