shell jacket vs tuxedo

shell jacket

noun
  • The jacket of a shell suit. 

  • A short jacket reaching the hips, once part of military uniforms. 

tuxedo

noun
  • The entire suit complementing and including this jacket. 

  • A typically black formal jacket worn by men. 

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