cat-o'-nine-tails vs flagellum

cat-o'-nine-tails

noun
  • A scourge (multi-tail whip) having nine, often knotted, whipcords, formerly used for flogging as naval punishment. 

  • A similarly constructed leather nine-tail whip, as used in British penal colonies and certain armies. 

flagellum

noun
  • A whip 

  • In protists, a long, whiplike membrane-enclosed organelle used for locomotion or feeding. 

  • In bacteria, a long, whiplike proteinaceous appendage, used for locomotion. 

How often have the words cat-o'-nine-tails and flagellum occurred in a corpus of books? (source: Google Ngram Viewer )