ramjet vs turbo

ramjet

noun
  • A jet engine in which forward motion forces air into an inlet, compressing it (as opposed to having a pump type device compressing the air for combustion with fuel), and where combustion is subsonic. 

turbo

noun
  • a turbine 

  • A turban shell. 

  • Autofire. 

verb
  • To autofire. 

adj
  • Very, super, etc.; usually relating to a qualitative value (as opposed to quantitative). 

  • Causing or relating to increased speed. 

  • With rapidly-increasing blind levels. 

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