cat's whiskers vs last word

cat's whiskers

noun
  • Something considered to be outstanding. 

  • Java tea (Orthosiphon aristatus) 

last word

noun
  • The finest, highest, or ultimate representative of some class of objects. 

  • Concluding remark; final advice, instructions, or observation. 

  • The final statement uttered by a person before death. 

  • A final decision or remark, or the right to make one. 

How often have the words cat's whiskers and last word occurred in a corpus of books? (source: Google Ngram Viewer )