big toe vs extremity

big toe

noun
  • The largest toe (usually) on each human foot (i.e. the toe closest to the other foot when the feet are flat on the ground, side by side, and the legs not crossed) or on a foot of certain other animals. 

extremity

noun
  • A hand or foot. 

  • The most extreme or furthest point of something. 

  • A limb (“major appendage of a human or animal such as an arm, leg, or wing”). 

  • An extreme measure. 

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