walking frame vs zed

walking frame

noun
  • A framework device used to support either an infant learning to walk or a person with walking difficulties. 

zed

noun
  • Something Z-shaped. 

  • The name of the Latin-script letter Z. 

  • Sleep. 

  • A zombie. 

verb
  • To sleep or nap. (Compare zzz, catch some z's.) 

  • To zigzag; to move with sharp alternating turns. 

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