agglomerate vs upheap

agglomerate

verb
  • To wind or collect into a ball; hence, to gather into a mass or anything like a mass. 

adj
  • collected into a ball, heap, or mass 

noun
  • A collection or mass. 

  • A mass of angular volcanic fragments united by heat; distinguished from conglomerate. 

  • An ice cover of floe formed by the freezing together of various forms of ice. 

upheap

verb
  • To pile or heap up; accumulate. 

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