flail vs whank

flail

verb
  • To wave or swing vigorously 

  • To beat using a flail or similar implement. 

  • To thresh. 

  • To move like a flail. 

noun
  • A weapon which has the (usually spherical) striking part attached to the handle with a flexible joint such as a chain. 

  • A tool used for threshing, consisting of a long handle with a shorter stick attached with a short piece of chain, thong or similar material. 

whank

verb
  • To beat; to thrash; to whip; to lash. 

  • To cut, especially to cut off a large portion. 

noun
  • A strike with the fist; a blow; a knock. 

  • A large portion, slice or lump. 

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