backslash vs flail

backslash

verb
  • To escape (a metacharacter) by prepending a backslash that serves as an escape character, thereby forming an escape sequence. 

noun
  • The punctuation mark \. 

  • Used erroneously in reference to, or in reading out, the ordinary slash, that is, the punctuation mark /. 

  • |passage= […] I was trying to find a web-site for which I had been given the following address: http://www.isop.ucla.edu/pacrim/pubs/korjournal.htm. […] I began to work backwards, removing first the last part of the address following the last backslash (/korjournal.htm).}} 

flail

verb
  • To beat using a flail or similar implement. 

  • To wave or swing vigorously 

  • To thresh. 

  • To move like a flail. 

noun
  • A weapon which has the (usually spherical) striking part attached to the handle with a flexible joint such as a chain. 

  • A tool used for threshing, consisting of a long handle with a shorter stick attached with a short piece of chain, thong or similar material. 

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