downer vs killjoy

downer

noun
  • Something or someone disagreeable, dispiriting or depressing; a killjoy. 

  • A livestock animal that has collapsed. 

  • A negative drug trip. 

  • A form of industrial action in which workers down tools and refuse to work. 

  • A drug that has depressant qualities. 

killjoy

noun
  • A person who is anti-fun, or prevents others from having fun. 

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