crewel vs tracery

crewel

noun
  • Worsted yarn, slackly twisted, used for embroidery. 

verb
  • To make (embroidery) using the crewel method. 

tracery

noun
  • A delicate interlacing of lines reminiscent of the architectural ornament. 

  • Bars or ribs, usually of stone or wood, or other material, that subdivide an opening or stand in relief against a door or wall as an ornamental feature. 

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