gallet vs slither

gallet

noun
  • A splinter of stone inserted into the wet mortar of masonry. 

verb
  • To use this masonry technique. 

slither

noun
  • A limestone rubble. 

  • A sliver. 

verb
  • To move about smoothly and from side to side. 

  • To slide 

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