muck about vs slummock

muck about

verb
  • To be playful; full of fun and high spirits; to not treat the situation seriously. 

  • To do random unplanned work or spend time idly 

  • To attempt to do something with a piece of equipment without understanding how it works. 

slummock

verb
  • To behave awkwardly or clumsily 

  • To behave lazily or indolently 

noun
  • A slovenly person 

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