submerge vs upheap

submerge

verb
  • To engulf or overwhelm. 

  • To sink out of sight. 

  • To put into a liquid; to immerse; to plunge into and keep in. 

upheap

verb
  • To pile or heap up; accumulate. 

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