grab bag vs interfusion

grab bag

noun
  • A moderately large bag of crisps or other snack, intended for sharing. 

  • A gift, purchase, etc. whose contents are concealed until after a selection is made. 

  • A bag containing essential items, which can be easily picked up and taken in an emergency. 

  • Any random assortment, selection or possibility. 

interfusion

noun
  • Mutual fusion or blending 

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