momentarily vs slap-bang

momentarily

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

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

  • Progressively; moment by moment. 

slap-bang

adv
  • directly or immediately 

  • in a violent or sudden or noisy manner 

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