frow vs weaker sex

frow

noun
  • A woman; a wife, especially a Dutch or German one. 

  • A cleaving tool with handle at right angles to the blade, for splitting cask staves and shingles from the block; a frower. 

adj
  • Brittle; tender; crisp 

weaker sex

noun
  • Women; the female gender. 

  • Used other than figuratively or idiomatically: see weaker, sex. 

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