beaver vs work like a horse

beaver

verb
  • To work hard. 

  • To cut a continuous ring around a tree that one is felling. 

  • After being doubled, to immediately double the stakes again, a move that keeps the doubling cube on one’s own side of the board. 

  • To form a felt-like texture, similar to the way beaver fur is used for felt-making. 

  • To spot a beard in a game of beaver. 

noun
  • A hat, of various shapes, made from a felted beaver fur (or later of silk), fashionable in Europe between 1550 and 1850. 

  • Beaver cloth, a heavy felted woollen cloth, used chiefly for making overcoats. 

  • A brown colour, like that of a beaver. 

  • The fur of the beaver. 

  • The pubic hair near a vulva or a vulva itself; (attributively) denoting films or literature featuring nude women. 

  • Beaver pelts as an article of exchange or as a standard of value. 

  • A woman, especially one who is sexually attractive. 

  • A game, in which points are scored by spotting beards. 

  • A semiaquatic rodent of the genus Castor, having a wide, flat tail and webbed feet. 

  • A beard or a bearded person. 

  • A move in response to being doubled, in which one immediately doubles the stakes again, keeping the doubling cube on one’s own side of the board. 

work like a horse

verb
  • To work very hard; to toil. 

How often have the words beaver and work like a horse occurred in a corpus of books? (source: Google Ngram Viewer )