gruel vs hairball

gruel

noun
  • semen 

  • A thin, watery porridge, formerly eaten primarily by the poor and the ill. 

  • punishment 

  • something that lacks substance 

verb
  • ejaculate 

  • To exhaust, use up, disable 

  • to punish 

hairball

noun
  • A small wad of fur or mass of hair formed in the digestive system of a cat or other animal, from hair ingested while grooming. 

  • A messy, tangled, intractable issue. 

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