convolute vs intervolve

convolute

verb
  • To fold or coil into numerous overlapping layers. 

  • To confuse, mix up (something) with something else. 

  • To make unnecessarily complex. 

adj
  • Convoluted. 

  • Coiled such that one edge is inside, and one outside the coil, giving a spiral effect in cross section. 

intervolve

verb
  • To twist or coil together. 

  • To involve one with another. 

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