jitterbug vs nervous Nelly

jitterbug

verb
  • To dance the jitterbug. 

noun
  • An uptempo jazz or swing dance which embellishes on the two-step pattern and frequently incorporates acrobatic style swing steps. 

  • A jazz musician or aficionado. 

  • Synonym of diddley bow (“type of stringed instrument”) 

  • A nervous or jittery person. 

nervous Nelly

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