freemartin vs whelp

freemartin

noun
  • A female calf, born as twin with a bull calf, but sexually imperfect (often infertile). 

  • Any female animal born sterile or otherwise infertile. 

whelp

noun
  • A young offspring of a canid (ursid, felid, pinniped), especially of a dog or a wolf, the young of a bear or similar mammal (lion, tiger, seal); a pup, wolf cub. 

  • One of several wooden strips to prevent wear on a windlass on a clipper-era ship. 

  • An insolent youth; a mere child. 

  • A tooth on a sprocket wheel (compare sprocket and cog). 

verb
  • To give birth. 

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