gob vs slough shark

gob

noun
  • A whoopee pie. 

  • The mouth. 

  • A sailor. 

  • A lump of soft or sticky material. 

  • Waste material in old mine workings, goaf. 

  • Saliva or phlegm. 

verb
  • To pack away waste material in order to support the walls of the mine. 

  • To spit, especially to spit phlegm. 

  • To gather into a lump. 

slough shark

noun
  • northern pike 

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