labium vs purl

labium

noun
  • The lip against which pressured air is driven to produce sound in a recorder and in a pipe organ with flue pipes. 

  • The lip of a labiate corolla. 

  • A liplike structure; especially one of the two pairs of folds of skin on either side of the vulva. 

  • A liplike part of various invertebrates. 

  • A lower mouthpart of an insect that is formed by the second pair of maxillae united in the middle line. 

purl

noun
  • A gentle murmuring sound, such as that produced by the running of a liquid among obstructions. 

  • A tern. 

  • a heavy or headlong fall; an upset. 

  • A circle made by the motion of a fluid; an eddy; a ripple. 

  • A particular stitch in knitting; an inversion of stitches giving the work a ribbed or waved appearance. 

  • The edge of lace trimmed with loops. 

  • An embroidered and puckered border; a hem or fringe, often of gold or silver twist; also, a pleat or fold, as of a band. 

verb
  • To rise in circles, ripples, or undulations; to curl; to mantle. 

  • To use an inverted stitch producing ribbing etc. 

  • To flow with a murmuring sound in swirls and eddies. 

  • To decorate with fringe or embroidered edge 

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