infiltrate vs intercalate

infiltrate

verb
  • To invade or penetrate a tissue or organ. 

  • To cause to penetrate in this way. 

  • To surreptitiously penetrate, enter or gain access to. 

  • To send (soldiers, spies, etc.) through gaps in the enemy line. 

  • To pass through something by filtration. 

  • To move from a vein, remaining in the body. 

  • To cause (a liquid) to pass through something by filtration. 

noun
  • Any undesirable substance or group of cells that has made its way into part of the body. 

intercalate

verb
  • To insert a substance between two or more molecules, bases, cells, or tissues. 

  • To insert an extra month into a calendar for the same purpose. The Hebrew calendar has such a month. 

  • To insert an extra leap day into a calendar in order to maintain synchrony with natural phenomena. 

  • To insert anything somewhere (especially between other things), such as an affix into a word. (Compare interpolate.) 

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