moan vs weeper

moan

noun
  • a low, mournful cry of pain, sorrow or pleasure 

verb
  • To complain; to grumble. 

  • To say in a moan, or with a moaning voice. 

  • To grieve. 

  • To make a moan or similar sound. 

weeper

noun
  • A pleurant. 

  • A weeping tree. 

  • A white border round the sleeve of a mourning dress. 

  • A widow's crape veil. 

  • A hired mourner. 

  • A thing that slowly leaks liquid. 

  • A person who weeps. 

  • A crape hatband. 

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