maid vs weaker sex

maid

noun
  • A girl or an unmarried young woman; maiden. 

  • A female servant or cleaner (short for maidservant). 

weaker sex

noun
  • Women; the female gender. 

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

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