waul vs yawl

waul

verb
  • To wail, to cry plaintively. 

yawl

verb
  • To cry out; to howl. 

noun
  • A fore-and-aft rigged sailing vessel with two masts, main and mizzen, the mizzen stepped abaft the rudder post. 

  • A small ship's boat, usually rowed by four or six oars. 

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